Thread: Keys & Key ways.

With a broach and a press you can cut a keyway manually. With out the use of a machine, mill, shaper, or lathe is there a manual way of cutting a key seat?

Also are keys always mild steel?

Originally Posted by DSEL74

With a broach and a press you can cut a keyway manually. With out the use of a machine, mill, shaper, or lathe is there a manual way of cutting a key seat?

Cape chisel and a hammer.

Originally Posted by DSEL74

Also are keys always mild steel?

No, I've used brass on occasion. Couple places in my boat I thought about using stainless steel.

PDW

Originally Posted by DSEL74

With a broach and a press you can cut a keyway manually. With out the use of a machine, mill, shaper, or lathe is there a manual way of cutting a key seat?

Also are keys always mild steel?

As you are talking about using a broach I assume you want to cut an internal key way in a pulley or such.

You can use a file to do it.

Get a flat file of the thickness (width) of the key way, cut it down the middle (with a friction disc) to make two narrow files which are able to fit through the hole of the shaft.

Grind the teeth off of one side of the small flat file, so you have one edge and one flat left for cutting.

Now use the edge of the file to cut the keyway.

The plain flat face of the file is used as a guide so as not to open out the slot excessively as you progress.

Works for me.

Keys can be hard or soft. Generally they are hard.

It is possible to use these slit down files as a rudimentary broach in a lathe tool holder and work the carriage back and forth (if you have a lathe).

Rob

A few ways are discussed here.
http://www.practicalmachinist.com/vb...s-done-242227/

I made one for a plastic gear wheel with a built in keyway that was 3mm wide on a 8 mm shaft using a Dremel cutting wheel and some needle files.
It was pretty rough and in the end I heated the plastic key area of the pulley until it got soft and pushed the pulley into the key way so it sort of moulded itself to whatever I had made.
It took me bloody ages as the shaft was very hard.

Hadn't heard of a cape chisel before, did a bit of googling. Looks like hard work and would require some skill to produce a long straight, and accurate seat. Be ok for the small half moon ones or just on the end of a shaft.

Start and end with a drilled hole.

Sounds like my spindle's key seat could have been hand done.
Keyway - 19.jpg

Oil groove were sometimes done the same way.



My current interest in how to coms from the restoration of my RSB Drill. The Keyways are all cut in long sleeves about 75mm long so filling isn't really an option as I would end up with a x shaped slot opening to a wide mouth each end. The same goes for chiselling the seat along the length of the spindle.

Still having an understanding of how it may have been made ro one off parts could be done it all part of the learning experience and joy in doing these projects.
Steel on steel with oil grooves, vs Bearing bronze, loose ball thrust bearings, belt drives and crowning pulleys, shaft & bore tolerances….Fascinating stuff

Originally Posted by DSEL74

Also are keys always mild steel?

Strictly speaking I'm not sure they are mild steel - the typical "make-a-key" stock is a medium carbon steel from memory. Something like 1020 or 1035?

Michael

Originally Posted by Michael G

Strictly speaking I'm not sure they are mild steel - the typical "make-a-key" stock is a medium carbon steel from memory. Something like 1020 or 1035?

Michael

I got the mild steel from a epay listing selling boxes of various keys. bit like those 100pcs mixed bolt sets. We all know how accurate epay sellers are.

So you are probably right.

Key can be made of different material depending on the application. For example, from memory on ski racing boats I think the key that holds the propeller on is brass. it's designed to be sacrificial just in case the prop hits something. I assume it's to shear the key rather than damage the $100,000+ engine/transmission when doing in excess of 8,000 RPM. Learnt that from someone who competed in the Southern 80 ski race a few years ago.

Assume some keys maybe stainless, hi tensile or MS too.

Simon

Broaches aren't cheap either, but the bigger expense is a press! I think there may have been one broach in my grandfather's tool box and I didn't know what it was at the time when I saw it, may have been something entirely different. I won't know until after I have moved and shifted all the boxes from the shed as well. At least a month away and it is going to play on my mind until I get in that darn box now!


I'd love to get a old screw press the H shape type with the big wheel on top.

Originally Posted by DSEL74

Broaches aren't cheap either, but the bigger expense is a press! I think there may have been one broach in my grandfather's tool box and I didn't know what it was at the time when I saw it, may have been something entirely different. I won't know until after I have moved and shifted all the boxes from the shed as well. At least a month away and it is going to play on my mind until I get in that darn box now!


I'd love to get a old screw press the H shape type with the big wheel on top.

Can we expect a "What's in Your Box" thread?

Dean

Little Douglas shapers can cut keyways.

Phil