About Us

Written by G.L. Huyett Marketing Department on 08/26/2020 with 0 comments

Grease Fitting Craftsmanship and Quality Assurance

The Huyett Heritage™ grease fitting line is the broadest line offered anywhere and is designed to meet the most exacting standards. The Vanguard™ line provides Heritage quality in non‑corrosive versions that can weather severe environmental extremes. All of these fittings meet the SAE J534 specifications for design and performance, and SAE J476 for threads. The Euro™ line provides Heritage quality in metric, British and European thread types. The Euro line meets DIN standards in nearly all applications. All of these lines are suitable for all original equipment applications, and conform to many user‑specific designs, including the John Deere™ series in agriculture.


Grease Fitting Craftsmanship


Our grease fittings are case hardened in sealed quence furnaces with complete atmospheric control. This eliminates scaling and ensures perfect control of case depth (0.005" - 0.009"). Hardness is controlled to a minimum of 83 on the Rockwell 15N scale.

Heritage, Vanguard, and Euro fittings are tested to ensure superior craftsmanship in case hardening.

Process Control

Heated to red hot, material absorbs carbon, making it harder. The heated fitting is then dropped in oil to cool. The fitting is re‑heated to scale back hardness to desired specification.


Automated assembly allows precise control of entire process. The ball check is inserted first followed by the spring. Then the lip is formed to hold components in place. Once assembly is complete, the fitting moves on to be tested for integrity and reliability.

Automation is used to assist in assembly of fittings to ensure quality.


Ball check is introduced. Spring follows ball check. Lip is rolled, completing assembly. The fitting is optically inspected.

Quality Assurance

Heritage, Vanguard, and Euro fittings are tested to the highest standards. Testing includes automated inspection for ball checks, load testing for harsh environments, and performance testing for reliability in the field.


We use optical inspection to ensure that no grease fitting leaves the facility without a properly installed ball check.

All Heritage, Vanguard, and Euro fittings are visually inspected to ensure a ball check is present.



Grease fittings are subjected to an impact test which simulates the abuse fittings may encounter in the field. This test ensures proper strength and hardness of the nipple.

Our grease fittings are tested to ensure that they will withstand the harsh environments they may be exposed to.


Weight is dropped in free fall against the fitting. If there is no damage, fitting passes inspection. If damage occurs, fitting does not pass.


Opening Pressure Test: Ensures the ball check and spring will operate properly by opening at a pressure less than 435 psi max, which is consistent with commercially practical and safe practices.

Back Pressure Test: Ensures the ball check will remain seated and that the fitting will not allow excessive leakage as pressure accumulates. 900 psi is the minimum pressure at which leakage could occur for standard fittings. Special leak‑proof designs can withstand pressures up to 10,000 psi.

Operating Pressure Test: The "Blowout" test determines the maximum operating pressures that the fitting can withstand without damage to the spring, ball, and fitting body. The testing apparatus is pressurized to 8,000 psi and is released at once.

Performance testing ensures reliability of our grease fittings in the field.

Performance Testing

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