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Bump Knurl Tool Holder

Select a knurl tool option in the drop-down menus (knurls are not included in the tool price).

SKU: 2275 Categories: ,

Product Description

About the Bump Knurl Tool Holder

Our bump knurl holder was designed primarily so customers who have CNC machines could add a knurling operation to their program, but it can also be used on a manual lathe. This holder is the same style that is used on full-sized CNC machines. It is held in position using the 3/8″ Insert Holder Tool Post (P/N 7600, not included).

Click on the image for a larger view.

P/N 2275 Bump Knurl Tool Holder shown engaged with a part.

Knurl size limitations with the Bump Knurl Tool

There are limitations to the knurl size and method of holding your part: Knurls from 40 TPI (threads per inch) and higher will work well on our machine. Coarser knurls from 32 TPI and lower will not work well. The exception to the rule is the diamond knurl. Because the diamond knurl is a male pattern, it can cut a larger TPI, so the 25 TPI that we offer is fine.

The bump knurl tool will handle stock diameters up to 1/2″ (12.5 mm), while it is turned in the lathe, creating a knurled pattern.

NOTE: The knurling tool was not designed for use with riser blocks.

Other size knurls for spiral, straight, or diamond patterns are also available.

Select the knurl(s) of your choice in the drop-down menu above.*

*NOTE: Each knurl is an additional cost.


The improper use of machine tools and their accessories can result in serious injury. Before using this tool, thoroughly read the instructions and make sure you understand its proper and safe use.


Always wear safety glasses when operating machine tools.

Download PDF 2275 Instructions

Instructions PDF Download

Download PDF Knurling Holders Comparison

Instructions PDF Download

Bump Knurling Tool demonstrated by guest craftsman, Jerry Kieffer

Body Material 6061 T6 Aluminum
Body Coating Black Anodized
Knurling Wheel Material High Speed Steel
Max Diameter Knurling Capacity 1″ (25mm)
22750 Bump Knurl Holder Body
36030 (4) .381 x .030 Washer (ID .190″)
36040 (2) 3/16″ x 3/4″ Dowel Pin
40520 (2) 10-32 x 3/16″ Cup Point Set Screw
Knurling tool(s) of your choice (not included)
Spiral KnurlsSKUPriceDetails
90° 40TPI Left Hand Spiral Knurl3609L$24.50Purchase
90° 40TPI Right Hand Spiral Knurl3609R$24.50Purchase
70° 50TPI Left Hand Spiral Knurl3610L$24.50Purchase
70° 50TPI Right Hand Spiral Knurl3610R$24.50Purchase
70° 80TPI Left Hand Spiral Knurl3611L$24.50Purchase
70° 80TPI Right Hand Spiral Knurl3611R$24.50Purchase
Straight KnurlsSKUPriceDetails
90° 40TPI Straight Knurl3618A$24.50Purchase
90° 41TPI Straight Knurl3619A$24.50Purchase
90° 47TPI Straight Knurl3620A$24.50Purchase
70° 50TPI Straight Knurl3622A$24.50Purchase
70° 53TPI Straight Knurl3623A$24.50Purchase
70° 60TPI Straight Knurl3624A$24.50Purchase
70° 70TPI Straight Knurl3625A$24.50Purchase
70° 80TPI Straight Knurl3626A$24.50Purchase
Diamond KnurlsSKUPriceDetails
90° 25TPI Male Diamond Knurl3627$42.00Purchase


We do not charge a flat rate for shipping because of the variations in weight for our products. Instead we charge you what the shipping company charges us. Our website uses a shipping calculator based on the daily rates for USPS and UPS based on the weight and destination of the shipment. You can also have us use your UPS/FedEx account number to charge your shipping to. Just enter it in the appropriate box on the checkout page.

Domestic orders are shipped Monday – Friday. Expedited orders must be placed by 9 am PST to ship the same day.

Orders shipping ground have a processing time of 7 working days for domestic orders and 14 working days for international orders. Click here for more information on our shipping and order policies.


Most merchandise can be returned within 30 day of the purchase date. A refund will be issued to the original form of payment at the original selling price. View our complete return policy and/or start your return online here.