Always wondered that..
Then I realised that a medium parallel knurle is say 0.5 mm pitch which translates to 0.08 mm on the diameter…so in any case as Michael says if sorts itself out…

Just go for it, Chris

The knurl is displacing metal, not cutting it.

… it should all sort itself out.

MichaelG.

.

Edit: I should just mention [before anyone else does ] that there is a rather exotic knurling system available that does have a cutting action … but most of us can't afford them.

Edited By Michael Gilligan on 29/07/2014 19:25:24

While I agree that you do get displacement, you will probably also generate some swarf – at least that's my experience, especially with brass.

As a matter of interest, when I was making a chuck key recently I used a fine straight knurl in the middle of the 1/4" handle. This increased the diameter by 10 thou and provided a good interference fit in the 1/4" hole.

Rod

Ok.
Speaking with no expertise beyond making 5000 to 7500 parts a week ,
knurled in a single pass .two wheels. Medium straight knurle
On drawn stock
Size of incoming stock did not once cause any issues with the knurles

That was for over seven years 48 weeks year.
There were metal fines in the knurles ( even with flood coolant).so some metal was cut…
Now the od of the part might have been selected carefully to suit but maybe not.
And yes every single nut was inspected for knurle…so some thing was working.

Edited By jason udall on 29/07/2014 21:10:32

Michael.
I don’t know about wisdom.
That was one part so not much experience other than setting the same job a few times… knurles lasted about 6 mo.
Most of those on a non cnc automatic…so depth and so forth set by finish not number.

What I mean is knurling ( well straight knurling) although it seems critical to start with the right diameter..it seems pretty tolerant…
Now thread rolling is a different horse entirely. …did a few hundred thousand of those to….
But when all well, thread rolling is far quicker than screw cutting, (even a dia box).

Back to knurling…parallel or straight knurle…pretty painless…diamond knurles. .trickier……

2100000. Eh.
Was I any good ?.
Well internal scrap on that part ran at about 0.2%…none from knurle..split equally between part too short.. ( end of bar mis feed) and tapping failure on the nut… ( generally feed rate too high..hydralic rate control thermal thing).
..but as I said, knurling on that job too easy to gain much expertise. ..
Now if you ask about the 10, 000 to 15 000. Per week 1/8 bsf nozzles..those were a bast**..you could get a thread to pas the no go and fail on the go gauge… again my guess would be feed rate and setting on the die box…..but never totally got rid of it..just some times popped up..

Edited By jason udall on 30/07/2014 21:23:28

.

Indeed it would, Kevin

For the curious [or tonight's Lotto winner] here is the Instruction Manual.

… We can but dream.

MichaelG.