Bridges drill refurb- replacement chuck shaft

[John RuddParticipant @johnrudd16576]

following on from my other thread, I may need to make a new shaft for the gearbox, the drill is a 2 speed job with a crash gearbox affair….

The shaft that emerges from the gear box carries the chuck and runs at the front in a 6200 bearing, supported at the rear with a nr bearing. The shaft carries the spur gear for the 2 speeds….the spur gear has a pb bush in the midle so it rides up/down the shaft as required…

So my question is what grade of steel is needed for a new shaft?

I'm guessing EN1 is going to be too soft…?

[John RuddParticipant @johnrudd16576]

[John RuddParticipant @johnrudd16576]

No recommendations on choice of material for this?

[Speedy Builder5Participant @speedybuilder5]

Silver steel – good for most things.
BobH

[LambtonParticipant @lambton]

John,

Make it from a good, UK made if possible, HT bolt grade 12.9 (imperial grade V) if you can get one or even a standard 8.8 (imperial grade R or S) would be much better than EN1.

HT bolts are good at resisting torque as well as high tensile loads.

Eric

[John RuddParticipant @johnrudd16576]

Gents,

Thanks for the replies, I had thought of SS, but maybe a but hard to machine?

I had considered the bolt route too but was concerned over the grade…

A happy bunny now, I'll go look for a bolt…

[FatgadgiParticipant @fatgadgi]

Hi John

I would guess a medium carbon steel such as EN8 may have originally been used.

This is not bad to machine and you can get free maching grades as well

Cheers Will

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