Chucks and jaws
Boring mill jaws (Vertical lathe chuck jaws)

1. Our boring mill jaws are entirely custom made to be used on vertical lathes, heavy duty horizontal lathes, deep-hole boring machines, roller grinders, welding positioners etc. These boring mill jaws clamp heavy and huge workpiece bolted onto chucks having parallel T-slots and radial T-slots. Usually one set of boring mill jaws include 4 or 8 pcs of jaws, but you can actually request for any number of boring mill jaws in one set according the application requirements;

2. These boring mill jaws clamp very huge and heavy workpieces on vertical borers or horizontal lathes. In some cases the works weights are upto hundreds of Tons. Sometimes clamping force boosting devices such as the clamping force boosting screws or the lever gear sets are fitted on the boring mill jaws so that one operator can effectively exert enough clamping forces to secure the heavy works;

3. For any sizes of boring mill jaws, one-piece and two-piece construction jaws can be custom made to meet your specific requirements. In case of two-pieces of designs, the boring mill jaws can also have soft top jaws as well as hard top jaws, thus it can be used in both rough machinings and fine machinings;

4. With the boring mill jaws bases made of one-piece casting steel and hardened & ground serrated top jaws made of forging alloy steel, whole quenched to a hardness of HRC 45 - 48. Compared with case hardened top jaws, whole-quenching hardened top jaws have much larger hardened depth which can endure a very long time wearing in clamping jobs;

5. Hardened and ground top surfaces of top jaws enable accuate positioning for workpieces. Soft jaws can be supplied for cases of clamping workpieces under fine machining;

6. Standard sizes of our boring mill jaws are 8"X6", 10"X7", 12"X7", 14"X7", 14"X9", up to 600mm X 320mm(length of base X bolt-hole-centerlines distance) or custom made referring to the size of the chuck on which the boring mill jaws will be mounted. Also boring mill jaws to be bolted on one-single radial T-slots on the chucks are available, with a bolt hole on each end of the jaw base. Sometimes this kind of boring mill jaws are used as workholding on welding positioners;

7. Lifting threaded holes on top of jaw base for lifting with eyebolts for safe and easy handling of the boring mill jaws;

8. Each set of boring mill jaws includes any number sets of boring mill jaws on requests. Accessories such as T-bolts and nuts, anti-thrusting cross key bars can be offered along with the boring mill jaws;

9. To enhance the clamping force of each boring mill jaw effectively, both clamping force booster gear sets and clamping force boosting screw rods can be chosen to fit on the boring mill jaws. 

8"x6" 2-Piece boring mill jaws supplied to a French customer who is in the valve manufacturing industry.


600x230mm Boring mill jaws, supplied to a USA customer who is a very large mining equipment manufacturer. This set of boring mill jaws were fitted on a vertical lathe with 8000mm swing diameter.


450x240mm Boring mill jaws supplied to a customer in nuclear equipment manufacturing industry, 450mm jaw base length, 240mm bolt-hole-centerlines distance (i.e., the distance between two adjacent T-slots parallel to each other on the chuck of the machine). This set of boring mill jaws were fitted on a CNC heavy duty horizontal turning and boring machine with 2500mm swing and 18000mm D.B.C., they clamped workpieces upto 120 Tons. Gear sets bolted on the jaw bases to boost effectively the clamping forces of the boring mill jaws so that one single operator can drive the jaws' screw rods to exert enough clamping forces onto the huge and heavy workpieces.


225 x 125mm 2-Piece boring mill jaws supplied to a USA customer who used it on his Youji CNC vertical lathe. 


300x180mm 2-Piece boring mill jaws for a Polish customer. This set of jaws are used on a Tos vertical boring mill with 4000mm chuck. A set of soft jaws for clamping works in fine machining were supplied with this set of 2-piece boring mill jaws. 

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