What's this part called please?

[Stanleymonkey]

Fixes the gear onto the shaft / axle in an old hand crank pillar drill.

Apologies for the awful photos.

Would like to know the proper name so I can buy some.

Any recommendations for a good supplier or just Amazon/Ebay type stuff is okay?

 

[Old.bodger]

Roll pin

 

[AES]

It looks like a ROLL PIN (I think).

If so, it shouldn't normally be bent out of straight.

Imagine a thick-ish slab of pastry, neatly cut and rolled into a circle until the two long edges almost touch.

That's a roll pin. They're actually made out of a fairly tough piece of steel, rolled into the circle as described above. The idea is that when free, as in your picture, the springiness of the steel makes the OD of the pin slightly too big to fit into a hole. But as one/both end/s of the pin will have a slight chamfer on the end, that allows the roll pin to be driven into the hole with a hammer, with the natural springiness of the steel causing a friction to hold the pin in place.

They're freely available in a range of diameters and lengths. Try a car parts & accessories place.

HTH

 

[Stanleymonkey]

That's brilliant thank you - it's not got any springiness left in it - it's been gradually slipping out and taking a few knocks I think. Need to get some new ones.

Thanks again

 

[BillHoughton]

They're generally tempered at a sweet spot between spring temper and a temper soft enough to be cut.

Check the hole; if the pin has been slipping, the hole could have been wallowed out - worn oval or otherwise sloppy. IF that's the case, and you have enough metal in the spot, you might be able to drill the hole out for the next larger size. But only if you must.

 

[Sachakins]

Also known as Mills pins or Groove Pins.

 

[Richard_C]

I've always known them as mills pins, but I'm old. Classic bodge if the pin comes out and gets lost on something not spinning fast, like a hand drill, is a nail with a deliberate slight bend tapped into the hole.

 

[AES]

Also known as Mills pins or Groove Pins.

Interesting. I've never heard either of those before. (But I have heard of the bent nail trick - not that I've ever used it of course - post below).

 

[Sideways]

Should be cheap.
Probably find some on ebay.
A good local engineers merchant may well have them in the shelf in many combinations of diameter and length.
When new they have a taper on both ends just for a few mm to help you feed them into the hole, they are then tapped home with a hammer and commonly a larger parallel pin punch from the set that you used to tap it out with.