Tapered square shank 7/8″ twist drill

[lescarmanParticipant @lescarman]

This has been in the back of my garage for years.It’s a Standard Tool Co.(US) 7/8″ twist drill with a tapered square shank.It’s a good guess that it arrived here with US equipment during WWII.It appears unused and the cutting faces look good.Surface condition is due to years of storage.

I can’t use it because I don’t have a suitable chuck and it would be a crime to scrap it.Normally I’d just turn down the shank to (say)1/2″ dia but it’s too large to go into the bore on my lathe.

Does anyone know any dodges to reduce the shank?Failing that, if anyone has any use for it in it’s present state please let me know and I’ll send it to you for the cost of P&P.

This is my first post on this site.I can’t find anywhere to post photos.Can anyone help?

Les

 

 

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[Mark EasingwoodParticipant @markeasingwood33578]

Hi Les,

Square tapered shanks are used in a Joiners Brace.

Pictures can be inserted using this icon.

 

[bernard towersParticipant @bernardtowers37738]

turn it between centres

[bernard towers]

On bernard towers Said:

turn it between centres

It is a twist drill. How would you put a centre into the pointy (cutting) end of it? What tool would you use to drill a centre hole in a tool that is itself designed to cut metal?

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It the shank really needed turning down, bore a 7/8″ hole into a piece of something and use body filler to glue the cutting end of the drill bit into that. Once the filler sets, grip that item in a headstock chuck, Use a tailstock centre at the other (square end). If the square end does not have a centre in it, it should not be hardened so one can be formed.

The drill bits are not used in a carpenter’s brace – they are used in a ratchet drill. In a YouTube video by DoubleBoost, I have seen an adaptor that goes from female square tapered to male tapered Morse taper (I think it was 3 Morse).

There is extensive discussion and an original catalogue picture here:

https://www.mig-welding.co.uk/forum/threads/drill-bits-with-square-taper-shank.73650/

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