JIC Fitting Size Chart: Thread Dimensions, Dash Sizes & Hydraulic Fittings Guide

JIC fittings are among the most widely used hydraulic and instrumentation fittings in industrial systems worldwide. From hydraulic power units and heavy construction machinery to oil and gas plants, aerospace systems, and industrial automation, JIC fittings are trusted for their reliability, high-pressure performance, and easy installation.

The term JIC stands for Joint Industry Council, referring to the standardization committee that developed the 37-degree flare fitting design commonly used today. JIC fittings are standardized under SAE J514 and are recognized throughout the hydraulic industry for their excellent sealing performance and interchangeability.

One of the most important references when selecting hydraulic fittings is the JIC fitting size chart. Engineers, technicians, and maintenance personnel rely on these charts to correctly identify fitting thread sizes, tube outside diameters (OD), dash sizes, and dimensions.

Improper fitting selection can cause:

• Hydraulic leaks
• Pressure drops
• System contamination
• Equipment damage
• Unsafe operating conditions

In this complete guide, we will cover:

• What JIC fittings are
• How they work
• Complete JIC fitting size charts
• Thread dimensions
• Pressure ratings
• Material selection
• Fitting identification
• Installation practices
• Troubleshooting methods

This article serves as a technical reference for anyone working with hydraulic tubing systems, instrumentation tubing, or fluid transfer applications.

---

What Are JIC Fittings?

JIC fittings are flare-type hydraulic fittings that use a 37-degree seating surface to create a metal-to-metal seal between male and female components. They are commonly used in high-pressure hydraulic systems because they provide excellent leak resistance and can be disconnected and reused multiple times.

The sealing mechanism is based on the contact between the male flare nose and the female flare seat. Unlike pipe threads that seal on the threads themselves, JIC fittings seal at the flare surface while the threads simply provide mechanical force.

Main Components of JIC Fittings

A standard JIC fitting system typically includes:

• Male fitting with external threads and 37° flare
• Female fitting with internal threads and matching flare seat
• Tube or hose connection
• Nut and sleeve (in tubing systems)

JIC Standards

JIC fittings are standardized under:

• SAE J514
• ISO 8434-2
• MIL-DTL standards in aerospace

These standards define:

• Thread dimensions
• Flare geometry
• Pressure ratings
• Material requirements
• Interchangeability

Common Materials

JIC fittings are available in several materials:

• Carbon steel
• Stainless steel
• Brass
• Aluminum

Stainless steel fittings are widely used in:

• Offshore systems
• Corrosive environments
• Semiconductor applications
• High-purity systems

Advantages of JIC Fittings

Some major benefits include:

• High-pressure capability
• Excellent vibration resistance
• Reusable connections
• Easy maintenance
• Wide global availability
• Good leak resistance
• Interchangeability between manufacturers

Limitations

Despite their popularity, JIC fittings also have limitations:

• Metal-to-metal seal may leak under severe vibration
• Improper torque can damage flare surfaces
• Contaminated flare faces reduce sealing performance
• Not ideal for ultra-high vibration systems compared to ORFS fittings

---

How JIC Fittings Work

JIC fittings operate using a 37-degree flare sealing system. When the male and female fittings are tightened together, the flare surfaces compress against each other, forming a high-pressure seal.

Sealing Principle

The sealing occurs at the flare surfaces rather than the threads.

The threads only:

• Pull the components together
• Maintain sealing force
• Prevent loosening

This design allows the connection to withstand significant hydraulic pressure without relying on thread sealant.

Installation Process

The installation process generally includes:

1. Preparing the tubing
2. Creating a 37° flare
3. Installing the sleeve and nut
4. Aligning the male and female fittings
5. Tightening to proper torque

Why the 37° Angle Matters

The 37-degree flare angle is critical because:

• It creates uniform sealing pressure
• Minimizes stress concentration
• Improves vibration resistance
• Prevents uneven loading

A mismatch in flare angle can immediately cause leaks.

Tube Preparation

Proper tube preparation is extremely important.

The tubing must be:

• Cut square
• Deburred
• Clean
• Properly flared

Damaged tubing can lead to:

• Cracked flares
• Improper seating
• Hydraulic leaks
• Reduced pressure capability

Torque Requirements

Under-tightening may cause leakage, while overtightening can damage:

• Flare surfaces
• Threads
• Tubing

Manufacturers provide recommended torque values based on fitting size.

---

JIC Fitting Size Chart

The JIC fitting size chart is one of the most important references used in hydraulic and fluid transfer systems. JIC fittings are widely used throughout industries such as hydraulics, oil and gas, aerospace, heavy equipment, agriculture, and industrial automation because they provide reliable high-pressure sealing and excellent reusability.

JIC stands for Joint Industry Council, and these fittings use a 37-degree flare seating surface to create a metal-to-metal seal between male and female fitting components.

Understanding JIC fitting dimensions is essential for:

• Proper hydraulic system design
• Leak prevention
• Correct hose and tubing selection
• Maintenance and troubleshooting
• Pressure reliability
• Safe operation

Improper fitting sizing can cause:

• Hydraulic leaks
• Pressure drops
• Tube cracking
• Connection failure
• Equipment downtime

This JIC fitting size chart guide explains:

• Dash sizes
• Tube OD dimensions
• Thread sizes
• Thread pitch
• Hydraulic fitting identification
• Pressure ratings
• Metric conversions

It serves as a technical reference for hydraulic engineers, technicians, hose fabricators, and industrial maintenance personnel.

---

Understanding JIC Dash Sizes

JIC fittings commonly use a dash size system.

The dash number represents the tubing outside diameter (OD) in sixteenths of an inch.

Dash Size Examples

• -2 = 2/16″ = 1/8″
• -4 = 4/16″ = 1/4″
• -6 = 6/16″ = 3/8″
• -8 = 8/16″ = 1/2″
• -16 = 16/16″ = 1″

This sizing method is widely used across hydraulic fittings and hose assemblies.

---

Complete JIC Fitting Size Chart

---

Metric JIC Fitting Size Chart

Many international hydraulic systems use metric tubing sizes.

The chart below provides approximate metric equivalents.

Metric conversion charts are especially useful when working with imported hydraulic equipment.

---

JIC Thread Sizes and Specifications

JIC fittings use straight Unified National Fine (UNF) threads.

The threads do not provide the hydraulic seal. Instead, the seal is created by the 37-degree flare seating surfaces.

Common JIC Thread Sizes

Why Fine Threads Are Used

Fine threads provide:

• Better clamping force
• Improved vibration resistance
• More precise torque control
• Better hydraulic reliability

---

JIC Male and Female Fittings

Male JIC Fittings

Male JIC fittings include:

• External straight threads
• 37° flare nose

Female JIC Fittings

Female JIC fittings include:

• Internal threads
• Matching 37° flare seat

When tightened together, the flare surfaces compress to form a metal-to-metal seal.

---

JIC 37-Degree Flare Angle

One of the most important features of JIC fittings is the 37-degree flare angle.

This flare design:

• Creates sealing pressure
• Handles high hydraulic loads
• Provides good vibration resistance

Importance of Correct Flare Angle

Using incorrect flare angles may cause:

• Hydraulic leaks
• Surface damage
• Poor sealing
• Premature failure

JIC fittings are sometimes confused with SAE 45-degree flare fittings, but they are not interchangeable.

---

JIC Hydraulic Pressure Ratings

Pressure capability depends on:

• Fitting size
• Material
• Wall thickness
• Manufacturer specifications

Smaller fittings typically withstand higher pressure.

Typical Pressure Ratings

Actual ratings vary depending on application conditions.

---

Common JIC Fitting Materials

JIC fittings are manufactured from various materials.

Carbon Steel JIC Fittings

Most common in hydraulic systems.

Advantages:

• High strength
• Cost-effective
• Excellent pressure capability

Stainless Steel JIC Fittings

Widely used in:

• Offshore systems
• Corrosive environments
• Semiconductor facilities
• Marine applications

Brass JIC Fittings

Common in:

• Fuel systems
• Pneumatic systems
• Lower-pressure applications

---

How to Identify JIC Fitting Sizes

Correct identification is critical for hydraulic maintenance.

Step 1: Measure Thread Diameter

Use calipers to measure thread OD.

Step 2: Measure Thread Pitch

Use a thread pitch gauge.

Step 3: Confirm 37° Flare Design

JIC fittings always use:

• Straight threads
• 37-degree flare surfaces

Step 4: Compare to JIC Size Chart

Match dimensions with a JIC fitting size chart.

---

Common JIC Size Identification Mistakes

Technicians commonly confuse JIC fittings with:

• SAE 45° flare fittings
• AN fittings
• BSP hydraulic fittings
• Metric hydraulic fittings

Incorrect fitting matching may cause:

• Leakage
• Thread damage
• Pressure failure

Always verify thread dimensions carefully.

---

Applications of JIC Fittings by Size

Small Sizes (-2 to -6)

Used in:

• Instrumentation systems
• Pilot hydraulic lines
• Pneumatic systems

Medium Sizes (-8 to -12)

Common in:

• Mobile hydraulics
• Industrial machinery
• Hydraulic power units

Large Sizes (-16 and Above)

Used in:

• Heavy equipment
• Offshore systems
• High-flow hydraulic systems

---

Why JIC Fittings Are Popular

JIC fittings remain extremely popular because they provide:

• High-pressure capability
• Excellent reusability
• Strong vibration resistance
• Easy maintenance
• Wide global availability

Their simple flare-seal design makes them ideal for many hydraulic applications.

---

Why Accurate JIC Size Charts Matter

Using the correct JIC fitting size chart helps ensure:

• Leak-free hydraulic operation
• Proper hose selection
• Correct tubing installation
• Pressure reliability
• Safe system performance

Incorrect fitting sizes may quickly lead to hydraulic failure.

---

JIC Thread Dimensions and Specifications

JIC thread dimensions and specifications are standardized to ensure proper sealing, interchangeability, pressure performance, and compatibility in hydraulic systems. JIC fittings follow the SAE J514 standard and use straight Unified National Fine (UNF) threads combined with a 37-degree flare sealing surface.

Unlike tapered pipe threads such as NPT, JIC threads do not create the hydraulic seal themselves. Instead, the seal is formed at the 37-degree flare surfaces while the threads provide mechanical force to hold the fittings together.

Understanding JIC thread dimensions is essential for:

• Hydraulic fitting identification
• Leak prevention
• Hose and tubing selection
• Pressure system reliability
• Maintenance and troubleshooting
• Safe hydraulic operation

Improper thread selection may result in:

• Hydraulic leaks
• Cross-threading
• Flare damage
• Pressure loss
• Equipment failure

This section explains JIC thread sizes, thread pitch, dimensional standards, tolerances, and fitting specifications used in hydraulic systems.

---

JIC Thread Standards

JIC fittings are standardized under:

• SAE J514
• ISO 8434-2

These standards define:

• Thread dimensions
• Flare geometry
• Pressure capability
• Tolerances
• Material requirements
• Interchangeability

The standards ensure fittings from different manufacturers can work together properly.

---

JIC Straight Thread Design

JIC fittings use straight UNF threads rather than tapered threads.

Why Straight Threads Are Used

Straight threads provide:

• Better alignment
• More accurate torque control
• Reduced thread distortion
• Easier assembly
• Improved reusability

The threads only create clamping force.

The actual hydraulic seal occurs at the 37-degree flare seating surfaces.

---

Common JIC Thread Sizes

The table below lists standard JIC thread dimensions.

These dimensions are widely used in:

• Hydraulic hoses
• Tube fittings
• Hydraulic adapters
• Fluid transfer systems

---

JIC Thread Pitch Explained

Thread pitch refers to the spacing between thread peaks.

In JIC fittings, pitch is usually expressed as:

• Threads per inch (TPI)

Example:

• 7/16-20 means:
  • 7/16″ thread diameter
  • 20 threads per inch

Why JIC Uses Fine Threads

Fine threads provide several hydraulic advantages:

• Better clamping force
• Improved vibration resistance
• More precise tightening control
• Better sealing stability

This is why UNF threads are commonly used in hydraulic systems.

---

JIC 37-Degree Flare Specifications

One of the most important JIC specifications is the 37-degree flare angle.

How the Flare Seal Works

The male fitting contains:

• External straight threads
• 37° flare nose

The female fitting contains:

• Internal threads
• Matching 37° flare seat

When tightened:

• The flare surfaces contact each other
• Metal-to-metal sealing occurs
• Hydraulic pressure is contained

Importance of Correct Flare Geometry

Improper flare geometry may cause:

• Leakage
• Uneven sealing
• Surface damage
• Reduced pressure capability

---

JIC Thread Tolerances

Thread tolerances are carefully controlled to ensure proper fit and interchangeability.

Why Tolerances Matter

Correct tolerances help prevent:

• Cross-threading
• Loose connections
• Galling
• Misalignment

Effects of Poor Tolerances

Incorrect thread tolerances may cause:

• Hydraulic leaks
• Thread damage
• Reduced service life
• Assembly difficulty

High-quality hydraulic fittings are manufactured with strict dimensional control.

---

JIC Male and Female Thread Dimensions

Male JIC Fittings

Male fittings include:

• External UNF threads
• 37° flare nose
• Straight thread geometry

Female JIC Fittings

Female fittings include:

• Internal threads
• Matching 37° flare seat

The threads generate clamping force while the flare surfaces create the seal.

---

JIC Thread Measurement Methods

Proper fitting identification requires accurate measurement.

Measuring Thread Diameter

Use calipers to measure:

• Outside thread diameter
• Major diameter

Measuring Thread Pitch

Use thread pitch gauges to determine:

• TPI value
• Thread compatibility

Inspecting Flare Surfaces

Inspect for:

• Scratches
• Dents
• Cracks
• Surface wear

Damaged flare surfaces may cause leakage even if the threads appear acceptable.

---

JIC Pressure Ratings by Thread Size

Pressure capability varies according to fitting size.

Smaller fittings generally handle higher pressure because they have:

• Smaller sealing areas
• Lower stress concentration

Typical JIC Pressure Ratings

Actual pressure ratings depend on:

• Material
• Manufacturer
• Temperature
• Application conditions

---

JIC Materials and Thread Performance

Material selection affects thread durability and sealing reliability.

Common JIC Materials

• Carbon steel
• Stainless steel
• Brass
• Aluminum

Stainless Steel JIC Fittings

Widely used in:

• Offshore systems
• Corrosive environments
• Semiconductor facilities
• Marine applications

Carbon Steel JIC Fittings

Most common in hydraulic systems due to:

• High strength
• Cost-effectiveness
• Excellent pressure performance

---

JIC vs Other Thread Standards

JIC fittings are often confused with other hydraulic thread systems.

JIC vs SAE 45° Flare

Major difference:

• JIC uses 37° flare
• SAE flare uses 45°

They are not interchangeable.

JIC vs NPT

NPT fittings:

• Use tapered threads
• Seal on threads

JIC fittings:

• Use straight threads
• Seal on flare surfaces

JIC vs BSP

BSP fittings differ in:

• Thread angle
• Thread pitch
• Sealing method

Mixing incompatible threads may cause failure.

---

Common JIC Thread Identification Mistakes

Frequent mistakes include confusing:

• JIC and AN fittings
• JIC and SAE flare fittings
• JIC and BSP threads
• Inch and metric fittings

Incorrect identification may result in:

• Thread damage
• Leakage
• Unsafe operation

Proper measurement tools should always be used.

---

Why JIC Specifications Matter

Following proper JIC specifications ensures:

• Leak-free hydraulic operation
• Safe pressure containment
• Correct fitting compatibility
• Reliable maintenance
• Long-term service life

Improper fitting dimensions may quickly cause hydraulic failure.

---

JIC Fitting Types

JIC fittings are available in numerous configurations to suit different hydraulic layouts.

Straight Fittings

Straight fittings connect tubing in a linear direction and are the simplest JIC design.

Elbow Fittings

Available in:

• 45-degree
• 90-degree

Used where space is limited.

Tee Fittings

Allow flow splitting or combining.

Common in:

• Hydraulic manifolds
• Instrumentation systems
• Pressure measurement lines

Cross Fittings

Used for four-way connections.

Bulkhead Fittings

Designed to pass through panels or walls while maintaining sealing integrity.

Swivel Fittings

Allow rotational movement during installation and reduce hose twisting.

Reducer Fittings

Connect different tubing sizes together.

Adapter Fittings

Common adapters include:

• JIC to NPT
• JIC to BSP
• JIC to ORB
• JIC to ORFS

These adapters are widely used in mixed hydraulic systems.

---

JIC Fitting Materials and Pressure Ratings

Material selection plays a major role in fitting durability and pressure capability.

Carbon Steel JIC Fittings

Most common material in hydraulic systems.

Advantages:

• High strength
• Cost-effective
• Good pressure performance

Stainless Steel JIC Fittings

Used in:

• Offshore platforms
• Chemical plants
• Semiconductor facilities
• Marine systems

Benefits include:

• Excellent corrosion resistance
• High cleanliness
• Better chemical compatibility

Brass JIC Fittings

Common in:

• Low-pressure systems
• Pneumatics
• Fuel systems

Aluminum JIC Fittings

Popular in:

• Aerospace
• Racing
• Lightweight hydraulic systems

Pressure Ratings

Pressure ratings vary significantly based on:

• Size
• Material
• Temperature
• Manufacturer

Typical hydraulic ratings range from:

• 1,500 psi
• 3,000 psi
• 6,000 psi

Some specialty fittings exceed these values.

Temperature Limits

Temperature capability depends on:

• Material
• Sealing surface
• Hydraulic fluid

Extreme temperatures can reduce sealing performance.

---

JIC vs Other Hydraulic Fittings

Hydraulic systems use many fitting types, and understanding the differences is important.

JIC vs AN Fittings

JIC and AN fittings are very similar.

Main differences include:

• Manufacturing tolerances
• Aerospace certification requirements
• Material quality

AN fittings are generally used in aerospace applications.

JIC vs ORFS

ORFS fittings use an O-ring face seal.

ORFS advantages:

• Better leak prevention
• Superior vibration resistance

JIC advantages:

• Simpler design
• Lower cost
• Easier maintenance

JIC vs NPT

NPT fittings:

• Use tapered threads
• Seal on threads
• Require thread sealant

JIC fittings:

• Use flare sealing
• Use straight threads
• Typically easier to disconnect

JIC vs BSP

BSP fittings are common outside North America.

Differences include:

• Thread angle
• Thread pitch
• Sealing method

Mixing JIC and BSP fittings is not recommended.

JIC vs Compression Fittings

Compression fittings use ferrules to grip tubing.

Compression fittings are common in:

• Instrumentation
• Gas systems
• High-purity applications

JIC fittings are more common in high-pressure hydraulics.

---

How to Measure and Identify JIC Fittings

Correct identification is critical for maintenance and replacement.

Step 1: Measure Thread Diameter

Use calipers to measure the outside thread diameter.

Step 2: Determine Thread Pitch

Use a thread pitch gauge.

Step 3: Identify the Flare Angle

JIC fittings use a 37-degree flare.

This is one of the most important identification features.

Step 4: Determine Dash Size

Compare measurements to a JIC fitting chart.

Common Identification Errors

Frequent mistakes include confusing:

• JIC with SAE 45°
• JIC with AN
• JIC with BSP
• JIC with metric fittings

Visual Identification

JIC fittings usually have:

• Straight threads
• 37° flare nose
• Fine threads

Hydraulic Fitting Identification Kits

Professional technicians often use dedicated fitting kits for quick identification.

---

Applications of JIC Fittings

JIC fittings are widely used in hydraulic, fluid transfer, fuel, lubrication, and instrumentation systems because they provide reliable high-pressure sealing, excellent durability, and easy maintenance. Their 37-degree flare sealing design makes them one of the most trusted fitting standards in industrial and mobile hydraulic applications worldwide.

JIC fittings are especially popular because they offer:

• High-pressure capability
• Good vibration resistance
• Reusability
• Easy installation
• Wide availability
• Excellent compatibility with hydraulic tubing and hoses

These advantages make JIC fittings suitable for many demanding industries and operating environments.

---

Hydraulic Systems

Hydraulic systems are the most common application for JIC fittings.

They are extensively used in:

• Hydraulic pumps
• Hydraulic cylinders
• Valves
• Hydraulic manifolds
• Power units
• Hose assemblies

Why JIC Fittings Are Popular in Hydraulics

JIC fittings are ideal for hydraulics because they provide:

• Reliable metal-to-metal sealing
• Strong pressure performance
• Easy hose replacement
• Good resistance to pressure pulsation

Their reusable design also simplifies maintenance and repair operations.

---

Mobile Hydraulic Equipment

JIC fittings are heavily used in mobile hydraulic machinery where equipment operates under vibration and dynamic loading conditions.

Common Mobile Equipment Applications

• Excavators
• Bulldozers
• Loaders
• Forklifts
• Cranes
• Mining trucks
• Agricultural machinery

Advantages in Mobile Equipment

JIC fittings provide:

• Durable connections
• Fast field maintenance
• Easy hose replacement
• High-pressure capability

Because mobile machinery often requires frequent maintenance, reusable fittings are highly beneficial.

---

Agricultural Machinery

Agricultural systems rely heavily on hydraulic power.

JIC fittings are commonly installed in:

• Tractors
• Harvesters
• Sprayers
• Irrigation systems
• Hydraulic attachments

Why Agriculture Uses JIC Fittings

Agricultural equipment experiences:

• Continuous vibration
• Outdoor exposure
• Dirt contamination
• Pressure cycling

JIC fittings perform well under these harsh operating conditions.

---

Oil and Gas Industry

JIC fittings are widely used throughout the oil and gas industry for hydraulic and fluid transfer systems.

Common Oil and Gas Applications

• Hydraulic control panels
• Valve actuation systems
• Offshore hydraulic skids
• Sampling systems
• Instrumentation tubing
• Pressure control systems

Offshore Applications

Stainless steel JIC fittings are commonly used offshore because they provide:

• Corrosion resistance
• High pressure capability
• Reliable sealing
• Long service life

---

Industrial Hydraulic Power Units

Hydraulic power units (HPUs) commonly use JIC fittings throughout the system.

Typical HPU Components Using JIC Fittings

• Pumps
• Accumulators
• Reservoir connections
• Pressure manifolds
• Return lines
• Instrumentation ports

Benefits in HPUs

JIC fittings simplify:

• System assembly
• Maintenance access
• Hose replacement
• Hydraulic troubleshooting

---

Aerospace Applications

Specialized JIC-style fittings are widely used in aerospace hydraulic systems.

Aerospace Systems Using JIC/AN Fittings

• Aircraft hydraulic systems
• Fuel systems
• Landing gear hydraulics
• Flight control systems

JIC vs AN Fittings

AN fittings are aerospace-grade versions of flare fittings with tighter tolerances and stricter material requirements.

Both use:

• 37-degree flare sealing
• Straight threads

---

Marine Hydraulic Systems

Marine environments require fittings that resist:

• Corrosion
• Vibration
• Pressure cycling

JIC fittings are commonly used in:

• Ship hydraulic systems
• Steering systems
• Marine cranes
• Hydraulic winches

Stainless Steel Marine Applications

Stainless steel JIC fittings are preferred because they handle:

• Saltwater exposure
• Humidity
• Corrosive conditions

---

Construction Equipment

Construction machinery relies heavily on hydraulic systems.

JIC fittings are found in:

• Hydraulic cylinders
• Boom systems
• Steering hydraulics
• Attachments
• Hydraulic motors

Why Construction Equipment Uses JIC Fittings

Construction environments expose equipment to:

• Dirt
• Vibration
• Heavy loads
• Shock loading

JIC fittings offer durable performance in these demanding conditions.

---

Mining Equipment

Mining systems operate under extremely harsh conditions.

JIC fittings are commonly used in:

• Hydraulic drills
• Excavators
• Haul trucks
• Underground mining equipment

Mining Requirements

Mining applications demand:

• High-pressure performance
• Reliable sealing
• Strong vibration resistance
• Easy field maintenance

JIC fittings satisfy these requirements effectively.

---

Industrial Automation Systems

Industrial automation often uses hydraulic and pneumatic systems requiring reliable tube and hose connections.

Common Automation Applications

• Hydraulic presses
• Manufacturing equipment
• Robotics
• Industrial machinery

Benefits in Automation

JIC fittings provide:

• Reliable sealing
• Easy maintenance
• Fast replacement
• Consistent performance

---

Fuel and Lubrication Systems

JIC fittings are also commonly used in fluid transfer systems involving:

• Diesel fuel
• Lubrication oil
• Hydraulic oil
• Coolants

Advantages for Fluid Systems

They provide:

• Leak resistance
• Reusability
• Good flow capability
• Reliable sealing

---

Hydraulic Hose Assemblies

One of the most common applications for JIC fittings is hydraulic hose assemblies.

Typical Hose Applications

• Hydraulic equipment
• Mobile machinery
• Industrial hydraulic systems
• Offshore systems

Hose End Configurations

JIC hose ends are available in:

• Straight
• 45-degree
• 90-degree

This flexibility simplifies hose routing.

---

Instrumentation Systems

Although compression fittings dominate instrumentation systems, JIC fittings are sometimes used in:

• Hydraulic instrumentation
• Pressure gauges
• Hydraulic test equipment
• Fluid monitoring systems

---

Semiconductor Utility Systems

Some semiconductor utility systems use stainless steel JIC fittings in non-high-purity support utilities.

Typical Utility Applications

• Cooling water systems
• Hydraulic support systems
• Facility utilities

Ultra-high-purity gas systems typically use specialized compression fittings instead.

---

Heavy Equipment Manufacturing

Heavy industrial equipment manufacturers frequently standardize on JIC fittings because they provide:

• Reliable global availability
• Easy maintenance
• Strong hydraulic performance
• Interchangeability

This helps reduce spare parts complexity.

---

Why JIC Fittings Are So Widely Used

JIC fittings remain one of the most popular hydraulic fitting standards because they combine:

• High pressure capability
• Excellent reusability
• Strong sealing reliability
• Wide compatibility
• Easy maintenance
• Cost-effectiveness

Their simple 37-degree flare design continues to perform reliably across many industries.

---

JIC Fitting Installation, Maintenance, and Troubleshooting

Proper installation is essential for reliable operation.

Installation Procedure

Basic installation steps include:

1. Cut tubing square
2. Deburr tubing
3. Create proper flare
4. Install sleeve and nut
5. Align fittings carefully
6. Tighten to specification

Leak Testing

Leak testing methods include:

• Hydraulic pressure testing
• Bubble testing
• Pressure decay testing

Common Failures

Frequent issues include:

• Cracked flare
• Damaged threads
• Over-tightening
• Misalignment
• Vibration loosening

Preventing Damage

Best practices include:

• Using proper tools
• Avoiding contamination
• Applying correct torque
• Inspecting flare surfaces

Reusability

JIC fittings are reusable if:

• Threads remain undamaged
• Flare surfaces are clean
• No deformation exists

Troubleshooting Leaks

Leak troubleshooting should inspect:

• Flare damage
• Dirt contamination
• Improper torque
• Tube alignment
• Thread damage

Maintenance Recommendations

Routine inspection should check for:

• Corrosion
• Wear
• Vibration damage
• Leakage
• Loose connections

Preventive maintenance greatly improves hydraulic system reliability.

---

Conclusion

JIC fittings remain one of the most important hydraulic connection standards used throughout the world. Their 37-degree flare sealing design offers reliable performance, high-pressure capability, and excellent serviceability across a wide range of industries.

Understanding the JIC fitting size chart is essential for:

• Correct fitting selection
• Hydraulic maintenance
• Tube fabrication
• Leak prevention
• System safety

Whether working in oil and gas, hydraulics, aerospace, semiconductor utilities, or industrial automation, engineers and technicians rely on accurate JIC fitting dimensions and standards every day.

By properly identifying fitting sizes, understanding thread specifications, selecting the correct materials, and following proper installation practices, hydraulic systems can achieve long-term reliability and safe operation.

ORFS Fitting Size Chart – O-Ring Face Seal Size Chart

NPT Thread Chart: Complete Dimensions, Sizes, Standards, and Engineering Guide