I had been using a torch to heat the end of the cotter crank for about 2 minutes before pounding out a stubborn cotter. I would heat until grease started bubbling from the spindle area and then it was fairly easy to extract those hellaciously-tight cotters.

I recently followed another thread somewhere and saw that someone came up with a nice-looking cast-iron press using a Harbor Freight chain-breaker, so I bought one for $8 and crafted a slightly different version. So far, it has done two rebuilds with relative ease, but I still heat each crankarm with the torch for at least a minute before really cranking on this cheap tool. Shown is what I came up with, after shortening and reinforcing the thin drive pin with an alloy sleeve. The big main screw has some hardening to it, and drilling it out used up a couple of 25/64" drill bits iir.
I'm so glad to have a smooth-turning bottom bracket (now with grade-25 ball bearings) in my Steyr Clubman. It is a huge improvement, to my surprise, and I put another 80 miles on her just this weekend.
The Steyr cup races appeared to be very hardened, with machining marks still prominent. The spindle races looked great, and the threading turned out to be English.

^Looks like a nice tool.

I've been thinking about modifying a C-clamp by JB welding a socket to the end of a c-clamp and removing the other swivel end, then filing the end under the swivel to create a nice contact point for the pin.

In the meantime, I just use a socket and vise, which has worked every time...so far.

Also found a new Cotter Press for sale on ebay:

https://www.ebay.co.uk/itm/COTTERPIN-...item460ea20f71

Found a seller of a cotterpin press on ebay:

https://www.ebay.co.uk/itm/COTTERPIN-...item460ea20f71

heat works great, i had a stuck cotter on my tourist.. broke my improvised harbour freight press..drill out only made it harder to work on... in the end a nice smack with a hammer and a blow torch did the trick +1 on one thing not working everytime...

guys at my coop say to back out the nut level with the top of the cotter pin then use a hammer, that way you protect the top of the cotter and have extra surface area to hit with a hammer, this worked a few times.. but the threads don't last too many hits.. so if it doesn't budge after the fifth hit i would go another route...

I just ran into this one today: any recommendations for removal of a cotter pin where the nut cannot be removed because the threads are stripped?

And as a side note, be picky about cotter pins you buy for installation! There are soft steel units (like the one I am struggling with now) that are essentially worse than useless.

I think Bikesmith Grade A is the way to go for new pins. The common, production ones are really soft. They are essentially pinched off, cheap rod stock whereas the Bikesmith ones are considerably better.

The upside of a soft metal cotter pin is you can drill it out to extract it fairly easily. FWIW the Raleigh cranks seem to like a 9.5mm cotter pin.

Just picked up the Bikesmith cotter pin press. It is charming how well it works and is half the price the Park presses go for on Ebay.

Its nice to use it to install the pin rather than using the pin's nut to cinch it in. No loose cranks- right the first time. Also installed the grade A cotter pins he sells, filed for the Raleigh crank. Sweet!

Great to know about those cotters Bikesmith sells.

I can't emphasize enough that cotters need to be hardened, to be suitable for hard use.

The pin should be pressed fully before tightening the nut, it's there only to prevent the pin from coming loose.

I have used the C clamp and socket and it worked well but I found a even better method. I grab the frame with out wheels and use a bench vice and socket. It does the job in 20 seconds every time. The bench vice has a lot of leverage and it will not slide off center like a C clamp.
Ed

Here's a link to a seller of a Cotterpin Press: https://www.ebay.co.uk/itm/COTTERPIN-...ht_1187wt_1142