Knurling tool design & wheel size

[Keith LongParticipant @keithlong89920]

Nige – on the page for Cromwell linked to above, when you see the picture of the parallel knurl there is a highlighted heading "more information", click on that and you'll find the diamond knurls. The picture is just a typical knurl wheel of a given size. if you look to the left side of the page you'll see a menu, against knurls it says 56 entries so you've quite a few to go at.

[Neil WyattModerator @neilwyatt]

Yes, hard to find knurls. Years ago I rang up a used tool dealer who said they weren't sure what they had. I said, don't worry, just send me a pair that matches – they sent me a little bag with several mixed knurls, straight and diamond of various pitches, used but all in good nick. A really nice gesture and it's great to be able to choose a knurl to suit the job.

Neil

[Ed DuffnerParticipant @edduffner79357]

I bought some diamond pattern knurls from Ebay. Two sets had off-center holes and another had the same direction, yet another set had burrs left on the edge from manufacturing which destroyed any pattern made by the knurl. In the end I spent a lot of time making my own.

Ed.

[Bruce EdneyParticipant @bruceedney59949]

I got mine from Aliexpress. Seem fine **LINK**

Bruce

[Howard LewisParticipant @howardlewis46836]

Surprised that no one has mentioned Arc Euro.

They offer wheels for Fine, Medium and Coarse diamond cut knurls. At 26mm diameter they seem to be large, but I can see an advantage in that. Catalogue 10 lists at £13:07 a pair, but prices seem to vary according to the exchange rate.

Much prefer the clamp type, since much less likely to impose a side load on the workpiece, or the Mandrel bearings.

Howard

[pgk pgkParticipant @pgkpgk17461]

Arc Euro Trade, Warco, RDG, Chronos, Cutwel.. lots of suppliers. really don't see the problem here. Warco's prices looked pretty competative with straight and diamond options. I can';t remember where i got mine but did buy both types and I'm usually mean enough to check prices. 'Knurling wheels' rather than 'knurls' in the search term.

pgk

[NigeParticipant @nige81730]

pgk: There never was a 'problem'. I was looking for suppliers who offer a variety of sizes and people like Arceurotrade and WARCO only offer wheels as spares for tools they sell, often only in a single size.

As I am trying to design from scratch I was looking for suppliers that offer wheels with a range of dimensions so I had choices at this the design stage. I had missed Cromwell offering because I didn't delve deeply enough into their website but as it turns out they are expensive compared with Chronos who do offer the sort of range I was expecting to see and who I ordered from.

Cutwell have the range but are expensive and there are one or two others who manufacture for industry and appear to have the range but don't advertise their pricing.

[Kerrin GalvinParticipant @kerringalvin72662]

Hi Nige,

Here’s a link to my knurling tool. Simple to build, works great. The knurls, 4 pairs from China at $30 NZ delivered would be pretty hard to beat. The custom QCT holder on the other hand wasn’t cheep!

**LINK**

Cheers Kerrin

[Joseph Noci 1Participant @josephnoci1]

I purchased knurl wheels from Hofmman Group in Germany –

**LINK**

Was rather expensive ( 25 Euro..), but very good quality – I used 1 set in diamond pattern on 240 knurls on 40mm diameter X 60mm long knurl section, on 4340 Chrome-Moly Alloy ( untreated condition) and the wheels still look like new! I tried wheels from Cromwell, or the Cromwell agents in South Africa – I set lasted 3 shafts..Cromwell prices were 2/3 of the Hofmann wheels.

Also, just for info, I started with wheels 25mm diameter but thet greater contact area required almost double the pressure to create a good knurl – 15mm worked very well, but the wheel speed made the center pin take strain – 20mm diameter was the sweet spot. 4340 is not a nice steel to knurl..

Joe

[fishy-steveParticipant @fishy-steve]

Posted by fishy-steve on 13/06/2018 21:32:46:

I also made Toms knurling tool that pgk recommends and very good it is too. I will say though that I've found the correct size knurls are hard to come by.

I ended up making modified knurl holders to except knurls that are easier to find.

Steve.

Just to clarify my earlier post. Toms design calls out for knurls with a 1/4 bore. I found these difficult to source at the right price.

Steve.

[pgk pgkParticipant @pgkpgk17461]

Posted by fishy-steve on 16/06/2018 10:45:06:

Posted by fishy-steve on 13/06/2018 21:32:46:

I also made Toms knurling tool that pgk recommends and very good it is too. I will say though that I've found the correct size knurls are hard to come by.

I ended up making modified knurl holders to except knurls that are easier to find.

Steve.

Just to clarify my earlier post. Toms design calls out for knurls with a 1/4 bore. I found these difficult to source at the right price.

Steve.

It's been a while since I made my version of the above..and bought whatever knurls were available and adjusted the holders/spindles to suit. I can take it apart and measure if anyone wants.

pgk

[Mike PooleParticipant @mikepoole82104]

Have you considered a cut knurler? A more difficult design but they sound as though they are a step up in performance compared to a crush knurler.

Mike

[Roderick JenkinsParticipant @roderickjenkins93242]

Nige,

Gloster tooling do a range of knurl wheels **LINK**. I find knurling is a fairly forgiving process and a simple design like my commercial version (Denford Small Tools) works fine:

This takes 1/4 inch bore wheels. The pivots are simply roll pins. However, I have found that the width of some of the wheels I have is a bit variable against the stated size so a larger gap between the arms with an allowance for a packing washer or two might be a good design feature.

HTH,

Rod

[Neil WyattModerator @neilwyatt]

My homebrew knurling devices use phosphor bronze pins for the rollers.

Using a circlip on the left side allows safer working close to a chuck.

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