Clarkson 4" Hi-flow cutter

Hello every one, is somebody overhere formiliar with Clarkson cutters and Dedlock chuck's? Am looking for a holder or chuck for this cutter, Int 40. Tried to find out what thread this cutter has, I measure 22,80 diameter and 12 TPI.

1"x12 UNF doesn't fit. Does Clarkson have their own threadsize?? Would be fine if some one could help with this. Best regards Robert

Good morning.

I'm sure Clarkson used Whitworth/BSF thread forms on their Dedlock chucks, but they weren't a standard TPI.

You may find a suitable Dedlock chuck, but they're not common nowadays. My milling machine has a 5/8 UNC power drawbar, & tooling for it is much less common than say an M16 drawbar.

Cheers.

Stewart.

Edited By Bdog507 on 01/03/2023 08:21:20

Hint; **LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=103028&p=1

MichaelG.

7/8" is 22.225mm so I would guess 7/8" 12 TPI but would use a thread gauge to check if it is a 60° or 55° angle thread. You may be able to get a good macro picture with a digital camera or phone camera that you can measure with a protractor. There was a recent thread regarding the smaller threaded tooling for Autolock chucks and they use 20 tpi Whitworth (55° ) threads. Recent discussion on endmill threads

Martin C

Edited for unwanted smiley

Edited By Martin Connelly on 01/03/2023 08:44:58

Saw several advertisements from dedlock's with; 1" Whit x 12TPI. It does make sense, not easy to make yourself.Thanks for the response, best regards Robert

Ok, I think it's indeed 1" Whit x 12TPI as Stewart wrote earlier. Even saw an advertisement in the US with M24mmx1.75 thread! I cannot find a bolt with these measurements. So is the seller right about this?? Thanks for responding, best regards Robert

Robert, I came upon this site by accident but it looks like it may be worth keeping an eye on their stock

https://www.bimtalk.co.uk/cnc-metalworking-manufacturing/?s=Clarkson+deadlock+arbor

Clarkson tooling is normal Whitworth form threads but they used whatever TPI they deemed appropriate.

John

Edited By Bdog507 on 01/03/2023 09:29:42

A quick internet peruse could it be a double start 12 tpi in 1" size
https://www.cromwell.co.uk/shop/cutting-tools/hss-ripper-regular-series/clarkson-dedlock-150-rippa-1-1-2inch-l-ser/p/MGZ0611688M

This ad says 1" BSW, but at first glance it seems finer, so might confirm the above
https://www.lawson-his.co.uk/clarkson-32473-dedlock-200-chuck-50int-1b-p57837

These folk may be able to assist with the official spec.
https://www.clarkson-tool-cutter-grinders.com/products/clarkson/accessories/

Bill

Hello Bill, saw the first two above allready, allthough the "double start" or "2 start" as the ad says I do not understand what it means! The second is a pity that it is an INT 50 otherwise I woud contact the seller. The third is interesting sure I gonne give it a try! BTW it isn't only the thread but also the 38mm flange wich goes into the cutter is an issue. Try to load up some pictures this evening for a better look. best regards Robert

Thanks John, I've seeing them all passing by in my dedlock surch!

As the cutter body has a female thread it is likely to be the minor diameter being measured, so 22.8 would be about right for 1" x 12tpi if it's just been measured with a digi calliper

Edited By JasonB on 01/03/2023 13:07:43

If you're sure the cutter is a genuine Clarkson, how about this on eBay?
https://www.ebay.co.uk/itm/314221387792

The same seller has at least two, (plus one with a cutter, which could be 150 or 200)

See also for a cheaper one
https://www.ebay.co.uk/itm/285043042653

Sheffield Tooling Co suggests that the cutter is a Dedlock 200 depending on the size
https://www.ebay.co.uk/itm/334633338233

Bill

Edited By peak4 on 01/03/2023 13:14:27

Edited By peak4 on 01/03/2023 13:20:59

I guess everybody can see my album and intention I had in mind!

If you are measuring the pitch as 12 tpi, a double start thread that measures thus is, roughly-speaking, two 6 tpi threads parallel to each other.

You can do a quick check to confirm or deny it: Poke a scriber point into the vee of the thread and rotate the cutter 360 degrees. See how far the scriber point advances. If it is 1/12", the thread is single start. If it advances 1/6", the thread is double start.

Post number 8 here suggest multi-start also:

https://www.homemadetools.net/forum/large-slot-drill-sidelock-chuck-lathe-66573

Robert, where in the world are you, presumably not UK if you loaded the album in the evening in your time zone.

You're showing a photo of a Dedlock 200 arbor; doesn't that fit your cutter?

**LINK**

Bill

Edited By peak4 on 01/03/2023 17:32:39

Well, never too old to learn something I guess, the double start can be seen optically at the bottem of the cutter. Also the measuring as you discribed, 4mm advance at one rotation. 1/6" = 4,23mm.

The spigot on my Clarkson Dedlock holder is definitely 1" OD, 12tpi Whitworth thread form, and is 2-start.

Plenty of Dedlock holders on Ebay, which is a sure sign they are obsolete. I have enough Dedlock cutters to make it worthwhile having a holder. Like this one:

Andrew