Brass is soft and tends to cause less destructive behavior when impacting steel.
It surly can move steel due to its mass which is greater than steel.
In general a cubic foot of steel weighs approx. 575 pounds, in comparison to a cubic foot of brass or copper which weighs out at no less than aprox. 625 lb per cu. ft.
Do the math.
brass/copper is soft but 50 lbs. says something is gonna move, just in a lesser way.
Aluminum in comparison weighs 175 lbs per cu. ft.
They do make plastsic dead blow hammers that cause alomst nil destructive behavior to anything but the plastic face unless you are striking plastic.

The end game here is not to F/U the chrome.

Why would they engineer a weak threaded fastener to hold it in ? Explain please

I used a big bench vise with a socket on the most stubborn cotter I had to deal with and it worked. Needed a helper to hold the bike though.

Not sure if you are serious, but it's because the nut is only retaining it, keeping it from vibrating loose. If the threads were strong enough to pull the wedge tight, they would be about the same diameter as the cotter, which would leave no room for the tapered face. The use of a press/hammer to tighten the wedge is actually a rather elegant solution.

Just like a square taper crank, the nut/bolt only serves to keep the wedge in place--the friction of the wedge itself provides the connection.

There are numerous examples of tapered fasteners/joins elsewhere (old nails, for one, drill/lathe chucks, etc) that operate in a similar manner, if not an exact copy.

They're cotter pins in the UK. In the US they're called cotters. I differentiates them from pins that keep nuts from loosening.

I've never tried to remove or install a cotter with anything but a press. It has always made the job simple and quick.

You have lived a charmed existence my friend. May it always be so!

In the early seventies I worked for a bike shop that rented hundreds of English 3-speeds to Stanford students. Only one in fifty or so cotters presented a removal problem, but the ones that did made up in aggravation for their small number. For many years afterwords I suffered Post Cotter Psychic Distress Syndrome. In fact, come to think of it, I haven't worked on a bike with cotters since then.
Brent

Brent, any chance that shop was Campus Bike? I worked at its California Ave location from 1986-1990.

Neil,
Stanford Bike Coop, on University Avenue towards the bottom of the business district. I think he had closed up shop by the end of the seventies.

Besides renting used bikes to Stanford students this shop had one other distinct peculiarity:
At that time the Macy's department stores still had a sporting goods department and still sold bicycles. Twice a year they would run a trade-in promotion. Customers could trade in any old bike for a $10 discount on any new bike. My employer bought all of those trade-in bikes from Northern California for $5 each. He would haul them by the trailer-load to the shop where they would reside in a huge tangled pile, hundreds of them, at one end of our shop. During the winter months we would slowly work our way through the pile, refurbishing what we could for sale or rent. Fortunately for us this all took place before there were many of the really junky "Free Spirit" department store bikes being traded in. The pile of bikes was like something from a cheap horror movie: It just kept growing and growing no matter how fast we tried to reduce its size. When it got so large that it threatened to push the sales floor and the work stations right out the front door my boss began renting warehouses in East Palo Alto to store the overflow! I'm glad Macy's finally stopped that promotion or that pile would have eventually taken over the world.
Brent

Hah! I lived on Middlefield road a couple of blocks from University from 1982-83, and it sounds like that shop was gone by then. I’ll bet the neighbors were happy about that!

A brass cotter hammer is also safer to use.
Not only does it impart a firm impact to the cotter being struck it will also not re-bound like a steel-on-steel strike can.
This is a good thing. ;)
The brass cotter hammer & VAR press were kept in the service managers' area in our shop to not be used/abused for any other purpose.
Over decades of service the once flat hammer head was slightly convex from use. Excellent tools.

-Bandera

Because its a 1 time fastener. Reuse of the cotter pin is not ever suggested. I reuse unless there is a problem. I'm lucky the Bikesmith lives down the block from me.

I rode the cottering pin loose on the non-drive side of my Raleigh. No luck on the drive side yet however. On a side note, where would one purhase replacement cotter pins?

What kinds of presses are we talking about? Several in this thread have stated "I have a nice cotter press" but it functioned to no avail. I just got a Bikesmithdesign press from Mark Stonich, it's creator. Is this fine-looking tool failing you guys? It's basically a small C clamp with a massive threaded pin and a much more massive frame to transmit the force from the threaded pin to the crank arm, through the cotter to crank spindle interface.

@ josh23 Welcome to the Forums.

Replacement cotters can be had from Mark Stonich, Bikesmith.

BikeSmith Design and Fabrication

Check out his site. Lots of good info to be had there.

I have several bikes with cottered cranks, including three rather nice cranks on racy bikes that don't have a chain guard.

And I have several tools for cotters, including the Bikesmith Design tool. Though an admirable tool, it is made for a crank that has a generous space between chain ring and crank arm, clearance for the chain guard. The tool is alas useless on cranks with less clearance.

My preferred cotter press is a drill press vise, used with a wrench socket. I also have couple cheap tools from Harbor Freight that I have modified to serve as cotter presses.

If anyone wants to buy a lightly use Bikesmith Design cotter tool, a private message is in order.

I use a ball joint splitter, get the longer scissor type, crank down the nut and works everytime.

Sooner or later you are going to have to drill one out.

You'll know when, just don't waste any more time at that point. You're gonna need a new pin anyway and time is money.

Not always possible as said above, but sometimes you can remove the right BB cup with axle & crank, then use a hydraulic press. Drilling on the crank side sometimes is difficult because of the ring.