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Category: Retention Knobs
Thread Size: M20X2.5
Angle: 45
Knob Diameter: 0.746
L1 Length: 1.2180
L2 Length: 1.573
Flange Thickness: 0.312
Hole Diameter: -
Neck Diameter: 0.549
Pilot Diameter: 0.826
Shoulder Diameter: 1.218
Wrench Flat Diameter: 0.94
Socket Part #: RKW45M
Number: JM31115
Country of Origin: USA

This knob is a replacement for the following parts:

ManufacturerPart Number
Retention Knob Supply: R311-15
Sandvik: 393.2930-45 030
Command: RB5M-0001
Kennametal: RK45B T1M
Lyndex: B45-4500
Parlec: 4505TRK
For Machines (see disclaimer)*: Kitamura, Ooya, Pratt & Whitney

* Retention knobs are not interchangeable. Machines are only given as a reference, JMPP makes no guarantee this is the correct knob for your machine. Please call us at 1-800-322-7750 or email for knob identification help.

WARNING: The steel alloy used in this product contains chromium and nickel. This product can expose you to chemicals including chromium and nickel, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to