[arpruss]

I've got a Craftsman router that needs a new collet, and some online information suggests the Bosch collets may be the same size. From photos, they certainly *look* right.

I am wondering if some kind and helpful person could measure the collet thread (namely, the thread pitch and the outer diameter of the male part that the collet nut screws onto on the router) on one of the 1613/17/18/19 routers?

As far as I can measure, my Craftsman has an M20x1 thread.

 

[arpruss]

arpruss

I don’t have access to mine right now but it was either 19 or 20 mm by 1mm thread pitch. I’m leaning towards 20 mm as the right diameter. It’s the same as a bunch of DWs, Hitachi m12V2, m12vc, m12ve, plus I think the newer Makitas. It is a very common collet but most Sears routers were made by Ryobi (315.xxxxx) and I haven’t seen any Ryobis with that collet but maybe the newer ones use it.

Thanks!

Online information seems contradictory. I found some information that suggested that the Hitachi M12 routers use 20mm thread, but at the same time Amazon has an off-brand collet for the Bosch routers that is explicitly listed as M19x1. So I would be really grateful if someone with a Bosch 1613/17/18/19 could measure their thread to see if it's 19mm or 20mm.

 

[arpruss]

It's good to know that the M12V series has the same size as the 1617.

The ebay listings for the M12 collets have photos that says they are 20mm.
The Amazon listing for Big Horn collets that are supposed to be compatible with the Bosch 1617 (and other models) says it's M19x1.

For what it's worth I downloaded photos of Bosch collets and measured in Inkscape. One photo, from a repair site, had a nice top view with a 1" calibration grid. That gave me 19mm for the inner thread diameter, which corresponds to 20mm outer thread diameter, or M20. But unfortunately it was a low resolution picture so I am not confident I was measuring the right parts of it.

I also got a high resolution photo of the collet from Bosch's website. Unfortunately it was tilted, so I had to use trigonometry to estimate the tilt (24 degrees) and use a 1mm thread pitch to estimate the scale. This gave me 18.3mm inner diameter, which presumably corresponds to 19mm outer thread diameter, but there was no doubt a lot of error due to the use of thread pitch for calibration (hard to measure and need to correct for photo tilt) and perspective which I did not take into account.

 

[arpruss]

Which model Craftsman are you working with? Craftsman has had a lot of different routers over the years, and have more or less relabeled other manufacturer's routers, including Bosch. With knowing what model router you have, you maybe have better luck getting the correct fitting collet for your router.

320.17541. I've done a lot of searching and the only 1/4" collets I can find for it are used ones for around $38 on ebay, which seems really expensive. Sears' parts store has the 1/2" collet, but the 1/4" is no longer available. I could get the 1/2" collet and then get a 1/2 to 1/4 reducer, but I am uncomfortable in using an adapter on something that spins so fast.

I destroyed my 1/4" collet when I got a 1/4" spiral cut bit stuck in it. The best online techniques for removing bits (wedging a U-shaped piece of wood, pulling with gloves) don't work on a spiral cut bit, and eventually the only thing I could think of doing was to cut the collet to save the router. :-(

 

[arpruss]

With a spiral you should be able to remove the nut over the bit.

The nut was getting stuck on a wider part of the collet cone that was sticking out of the nut. The only way I could remove the nut was by cutting off the part of the collet that was blocking the nut. :-(

 

[arpruss]

I ordered the Bosch 1/4" collet from Amazon, and it's M20x1 and the thread fits my Craftsman 320-17542 perfectly (I didn't actually rout anything, as I don't have a 1/4" router bit at home right now).