Cut
Type Knurl Holders |
CUT TYPE Knurling is not widely used in U.S. market,
but common in the rest of the world. The knurling dies are skewed
(layed over 30°) to the work piece axis creating a cutting
action rather than a forming process. Often times when knurling
non-ferrous material (aluminum, brass, etc.) the forming action
work hardens the material causing the crest to become brittle and
break off. Not so with the cut type knurl - the milling action
leaves a sharp solid crest for a perfect knurl.
There are both single and two die holders available. Interesting is the fact
that to get the diamond pattern two straight tooth dies are used (on a two die
holder) and for a straight pattern a single helical die is used. It is believed
that the diameter of a finished knurled part can be more easily controlled with
this method; just remember you aren't increasing the diameter of the work piece.
Holder shanks can be mounted at right angle to the piece and always use plenty
of coolant to wash away chips.
It's best to experiment with the Speeds & Feeds to
get the best looking knurl, but generally a feed in the range of 0.07-0.2 mm/rev
and a surface speed of 15-55 m/min will work. With softer metals (aluminum & brass)
stay on the high end, but with stainless and other high alloys use the lower
end. For stainless steel, or other higher alloyed steels, you should expect lower wheel life than that obtained with "forming" wheels
With a fairly rapid infeed to the final minor diameter of the workpiece, cut type knurls will normally track on any diameter. If not, a small variation to the infeed rate, or blank diameter will normally correct any problem. Once established, the blank diameter should be held within +/- .025mm (.001"). Depth of the cut should be .5-.6mm
x pitch. The method of approach is very important to getting a good looking knurl.
On the end of the work piece, approximately 1-2 pitches wide, plunge the tool
straight into the part. After reaching the correct depth then traverse across
the part. Note: Do not just feed axially.
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Specifications / Pricing for Single Knurl Holders
Setup
Instructions for Single Wheel Cut Knurling
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SINGLE KNURL
HOLDERS |
These knurling tools will produce a straight knurl
using a 30° RH diagonal knurling die or a 30° RH diagonal
knurl with a straight knurling die. The knurl depth should be approximately
50% of the knurl pitch. Surface speed is in the range of 50-200
ft/min (depending upon material) with a feed rate of around .005"/Rev.
If the knurl is not parallel, adjust the head. Be sure to use plenty
of coolant to flush away the chips.
*Each time the wheels are changed, a high pressure graphite based lubricant should be applied to the bore and bushing to reduce the likelihood of the wheel seizing on the bushing. |
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DOUBLE KNURL HOLDERS |
These knurling tools will produce a 30° diamond
pattern using two straight knurling dies. Set the work diameter
on the tool scale by unlocking the socket head screws from the
rear and tapping to break the lock. The tool has to be mounted
in the machine on center. Use the fine adjustment screws to insure
both knurls are hitting equally. The depth of cut should be approximately
50% of the knurl pitch and feed at around .005"/Rev. Surface speed
should be in the range of 50-200 ft/min depending on material. Always have plenty of coolant flushing the work area.
*Each time the wheels are changed, a high pressure graphite based lubricant should be applied to the bore and bushing to reduce the likelihood of the wheel seizing on the bushing. |
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