Myford Super-7 (1955) – Headstock cap-scew size??

[flatlineParticipant @flatline]

Good evening all…

I am still very much a beginner and have had my Super-7 since May last year…. I have learnt enough to understand that now is the time to get the bed, saddle & cross-slide re-ground…

I have disassembled virtually everything, and am down to the last 4 bolts/cap-scews that hold the headstock to the bed.

So far I have got away with a selection of metric & AF tools, but these last 4 definitely need the right tool for the job.

Can anyone tell me what size Allen-socket I need to undo these please??

Many thanks.. 🙏

 

[bernard towersParticipant @bernardtowers37738]

if as you say you have af imperial sizes then you are there

[flatlineParticipant @flatline]

Unfortunately I don’t have any AF Allen-sockets…

I have an old Allen-key that has no markings but measures 0.215”/5.45mm across the flats… it fits, but it’s not ideal… as I say, it’s quite old & of unknown manufacture so I don’t know if those measurements reflect the actual size required??

any help greatly appreciated.

[Nigel Graham 2Participant @nigelgraham2]

“Getting away with” is about right. Normally, the fasteners on these lathes are all BSF, BSW and BA.

You risk rounded-off hexagons by using poorly-fitting spanners and keys – oh, and skinned fingers from spanners suddenly slipping off, but skin grows back.

[Martin KyteParticipant @martinkyte99762]

You need a TEE wrench on these as they will be very tight. Do get something that fits correctly.

 

[DiogenesParticipant @diogenes]

These are reliably good & you can buy them singly – for this particular application, I’d use a plain rather than a ball-end pattern.. ..you can shop around, obviously..

https://bondhus.co.uk/collections/t-handles

[JasonBModerator @jasonb]

A quick look on Myford’s site tells me they are 5/16BSF fixings. A google for that size screw spec says they are 7/32″ nominal hex so that is what you need. Sanity check 7/32″ is 0.218″ so close to the one you have

[flatlineParticipant @flatline]

JasonB – many thanks for your reply, progress will be swift now!!

[flatline]

On flatline Said:

Unfortunately I don’t have any AF Allen-sockets…

I have an old Allen-key that has no markings but measures 0.215”/5.45mm across the flats… it fits, but it’s not ideal… as I say, it’s quite old & of unknown manufacture so I don’t know if those measurements reflect the actual size required??

any help greatly appreciated.

Don’t mess about, buy a set of Imperial Allen keys, and avoid ‘too cheap’.  T-Handles are best if frequent use is likely.

An early  lesson painfully learned by me is that fasteners are easily damaged by ill-fitting tools, and the aggro that causes isn’t worth the risk!  A tight Allen socket that’s been distorted by an ill-fitting key becomes a major problem.  Ditto screw-heads and nuts and bolts damaged by misfit tooling.  Worth getting sets of tools that fit accurately.  Though 90% metric, I haven’t begrudged buying both metric and imperial Allen key sets.

Old tools must be in good condition, and that depends on their history.  Wrong size, and/or worn.   Any doubt, chuck ’em out!

My advice, don’t cheapskate on this one.

Dave

 

[JasonBModerator @jasonb]

I’d go with a 1/4 or 3/8 drive with 7/32″ hex, a ratchet or tee bar will give more leverage than a tee or L shaped key and extensions will give you the reach needed.

[noel shelleyParticipant @noelshelley55608]

Not entirely off topic ! I was faced with a number of 3/16″ af countersunk head bolts that were seized and had been attacked by the cabin boy who having butchered the heads gave up. For this size (4.75mm ) take a short 5mm hex key and hammer in to the bolt head, it will cut its own size and will give the best hope of success. Noel.

[Clive Brown 1Participant @clivebrown1]

My 7/32″ hex key is, as close as I can measure, within a tenth of a thou. of exact size, 0.2188. It’s a very snug fit in a 5/16″ allen screw. I think the OPs key at ~4 thou. less might seem quite slack at this size.

[Clive Brown 1]

On Clive Brown 1 Said:

My 7/32″ hex key is, as close as I can measure, within a tenth of a thou. of exact size, 0.2188. It’s a very snug fit in a 5/16″ allen screw. I think the OPs key at ~4 thou. less might seem quite slack at this size.

Agreed !!

Like so many things these days;  many are made “a little worse …”

For the job at hand, only the best is really good enough

MichaelG.

[noel shelleyParticipant @noelshelley55608]

is the key the OP using a 7/32″ or is it a 5.5mm ? Their very close. Noel

[Bill PhinnParticipant @billphinn90025]

Provided you use the right imperial hex bit, not an almost-there metric one, I’m with Jason on this: use a 1/4” or 3/8” breaker bar, sliding T or ratchet with extension if necessary. For tight spaces, wobble extensions are a good alternative to standard ones.

You’ll just need an imperial hex bit set (surely indispensable if you have a British lathe) and the relevant 1/4” or 3/8” square to 1/4” hex adapter.

Personally I rarely use Allen keys now on anything; it’s usually hex screwdrivers and one or other of the above.

[flatlineParticipant @flatline]

A set of long-reach hex-sockets purchased today, the 7/32” fitted perfectly & the headstock was removed within a few minutes.
many thanks for the advice 😎🇬🇧👍

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