Knurl Holders

        Knurling can be done with many types of holders made for knurling or with any holder (or machine) made for thread rolling.  Bump Knurling from the cross-slide with a single knurl is often the easiest method.  However, if a wide knurl must be applied, or the stock size is very small, this method might not be suitable as problems with excessive knurling pressure, or bending of the stock may result.  In this case a Straddle Type Holder should be used. 
        When Knurling from the cross-slide with straight knurls in a straddle type holder without a connecting gear train, a certain percentage of parts may be expected to double track as the two knurls are tracking independent of each other.  With knurls 30 TPI and finer the problem is minimal.
Bump Holders

Best Suited to shorter work or longer work if knurling can be done close to the chuck or tail stock.

Straddle Holders

Use Right Hand and Left Hand knurls to produce a diamond pattern also may be  traversed  to produce long knurl patterns.

Internal Holders
Often used to repair parts with slightly oversized holes.
Face Holders
Suitable for knurling narrow bands (especially on tubing).
Turret Mounted Holders

Mounts inline with the machine spindle.  Use Right and Left Hand knurls to produce diamond pattern.

Conical Holders
The best way to knurl on the face of a part.  A special conical knurl is required to provide correct tracking.
Self-Centering Holders
Pivoting Head floats to align with the part to be rolled.
Angular Bump Holders
For knurling on a chamfer.
Synchronized Rolling Heads
Used where rolled parts must be very precise, especially when they must fit a mating part.


Many specials can be made by modifying a stock holder.  Most stock holders are shipped within 1 - 2 days.
Simple Specials made from scratch usually require 1 - 2 weeks.

To order an altered stock holder, make a sketch of what you require, or find the catalog page with a holder that most closely resembles your required holder.  If possible, copy the page and draw an arrow next to the tool number of the closest match.  Then write down the changes, such as "C=7".  Include your name, phone number and the quantity of holders you require (if more than one).  Fax the page to Form Roll at (508) 755-5835, or email formroll@tiac.net.



For more information on knurling tool holders contact our holder division, Stafford Special Tools.