I’ve picked up a Record 4 1/2 plane. It’s missing the handle toe screw. Some googling tells me it’s a 7/32? 20tpi screw, which are very hard to get hold of (impossible so far). (I tried a frog screw but they are too short). So the solution is to tap out the hole.

Would I be better tapping to 1/4? UNC (20 tpi) or use 6 mm (which works out at 25.4 tpi)?

Many thanks in advance

If you have to buy the tap, you’ll probably find that the metric one will be cheaper.

All the various parts for these are usually available on eBay. No idea on cost but have you had a look there for a start?

https://www.ebay.co.uk/itm/122324917519
For the front handle

Nope, this is toe screw on the rear handle. It’s a little screw in front of the main bolt. I’ve been looking for a couple of weeks no with no luck.

7/32 x 25.4 = 5.55mm

tapping size for m6 = 5mm

you might wanna go bigger.

m8 x 1.25 – tapping size is 6.8mm. how deep is the hole?

I’d go for 1/4 UNC. Easy job and minimal change.

tapping size for 1/4″ unc is still smaller than 5.55mm you wont have full thread

What Jamie says. The Thread pitch of a M8 coarse (normal) thread is 1.25 mm, near the same as 20 tpi. you need to drill the old threads out with a new tapping drill (6.8 mm) then tap the threads in.

Try a few carboots, should get a whole plane for a few quid (for parts)??

Surely even buying this whole kit is cheaper than getting the correct drill and tap? Or as suggested a whole plane, at least this kit will give you shiny new knobs and screws all round.

https://www.ebay.co.uk/itm/192085796899

If you are in Essex I’ll do it for you i have a million m8 bolts too

Stick a 5mm drill down and go with the 1/4 20 unc there will only be a few thou of the 7/32 thread left and the tap will more than likely pick up on the original 20 tpi. Any local Engineering company will lend you a tap if they are half decent and someone there would probably tap it out for you, I certainly would if you need it doing

tapping size for 1/4″ unc is still smaller than 5.55mm you wont have full thread

But its same pitch so the tap will deepen the existing grooves. That’s what makes it the easy option.

Right fair enough. I ain’t got a 1/4 20tpi tap or even any 1/4unc bolts! Or even a 1/2″ spanner…

I like Nick and Smith’s logic. I’ve got done taps so that isn’t an issue.

Many thanks!