Full Grip Advantage

Full Grip Jaws are designed to grip the part more effectively without distorting thin-walled or odd-shaped parts and are available in Aluminum (most popular) Cast Iron and Steel. Full Grip Jaws maintain a 360 degrees of contact giving you a greater accuracy so parts cannot distort.

Our 6 inch to 15 inch are manufactured from aluminum extrusions so there is no porosity, unlike other companies that us Castings. The lightweight of the aluminum enables the chuck to rotate faster enabling the chuck to turn faster with less wear and tear on your machine. The benefits of lighter weight enhances shop efficiency and utilization.

Only three points of contact around the part is achieved with standard soft jaws.  This constant chuck pressure could damage the part and at high rotations and the part could distort between the contact points. Soft jaws should not be utilized on thin-walled or odd-shaped parts without modification.

Full Grip Jaws can be used in over 60 % of all your turning operations. Concentricity’s and close tolerances are easily and consistently maintained.  Another benefit is machine and tool life are greatly extended due to more effective application of coolants and chuck pressure.


So if your next workholding project has thin-walled parts or odd shapes let us assist you in the right Full Grip Application so you get the maximum benefits in your manufacturing process.

Alan Garey

Huron Machine Products



Serrate or Not?

Serrate or Not, That is the Question!
And some other tips!


We get a lot of customers that ask us serrated or not:

Harden serrated soft jaws with Diamond gripping serrations enhance the grip by penetrating the workpiece. When we evaluate a given design, the workpiece hardness and material is always factored in. Most of the time harden soft jaws with serrations are used for 1st operations. This is when the customers is getting aggressive with removing material. Hardened serrated soft jaws also last longer but we have assisted in several projects over the years were we use Fairlane Grippers. This is usually in a high volume production application with a casting style part.  The grippers can be adjusted to fit the workpiece.


Non-serrated griping serrated jaws or Soft Jaws are used in a second operation. When the workpiece needs to match the gripping surface. This allows the machinist to grip the workpiece without marring it.  Soft jaws come in several sizes and materials. Are standard off the shelf Soft Jaws covers 80% of the workholding applications. Encase were they do not we can design Special soft jaws to meet the specific application.


Whether using a Serrated Hard Jaw or Soft Jaw a close grip is recommended. Parts should be gripped as near the chuck face as possible to obtain maximum jaw force, minimize jaw yield, and reduce internal loading to enhance chuck life. We recommend that the jaw height not to exceed its length, and top jaw length should be the same as master jaw length. Grip diameters should exceed the diameter to be machined if possible. If this is needed then consider reducing machining forces. When gripping the workpiece always grip in the middle. Grip position of the top jaws should occur at approximately mid-stroke of the chuck. Never grip at the extreme inner limit of the jaw stroke.


So there is not a wrong answer to serrated or not. It’s more the
the application that dictates which one will work best for you.



Alan Garey
Huron Machine Products



The History of Jaw Lock Mountings

Sometimes we take for granted the Jaw Lock Mountings for Top Jaws.  Simon Fairman patented the Scroll Chuck in 1840. His son-in-law  Austin F. Cushman then started Cushman Inc. and started selling manual chucks with Tongue and Groove Jaw Lock Mountings. Manual chucks are still very popular and we still sell a lot of Top Jaws with Tongue and Groove Mountings.

In the 40’s Cushman then came out with a Power Chuck with an ACME Key Mount. They are two styles of Key Mounts, ACME and Square. The ACME top jaws were our most popular Top Jaw with the
height of sales during the oil boom in the 70’s.

The Japanese Power Chucks starting coming on the New CNC Lathes in the late 70’s with fine serrations, 1.5mm x 60. Because of the length of the serrations, it gives the machinist more flexibility with the mounts. The 1.5mm x 60 is now by far the most popular Top Jaw Style. The European Chucks also went to fine serration at that time using a 1/16 x 90 and 3/32 x 90 style serration. The European’s also came out with Quick Change Chuck that takes a metric style tongue and groove.

When mounting Top Jaws a total of six screws are needed for the three jaws. Socket head cap screws are used to clamp each jaw (with a long tee nut) to the chuck’s master jaw. Before mounting the jaws the mounting on the chuck and the jaws needs to be cleaned. If debris gets in between the jaw and the chuck it can cause the chuck to be off balance and the jaws will not repeat. This will cause the parts to have run out.

When ordering Top Jaws it’s important that you have the Chuck Make and Model number. This will ensure that the right Mounting Style for your chuck. We have been making Top jaws for over 70 years so we have a very extensive library of Top Jaws. But if for some reason we don’t we can make the Top Jaw from the dimensions you provide us. So as you can see Top Jaw mounts have come a long way but still have remained the same.

Alan Garey
Huron Machine Products

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