Thread: screw sizes on enfields
Retrieved: 06/02/2014
Before I start randomly trying stuff. Would anyone be able to tell me the thread sizes on the band screws, the nose cap screws, and any other you might happen to know... It seems to me that some of these screws are becoming the hardest parts to find. If I can find ones that will work without stripping stuff would be greatly appreciated. (I have both a #1 Mk3 and a #4 Mk2 that I'm resurrecting) I'm thinking that if I found round Allen heads to put in for the time being...
purple
04-28-2014
For the No.4 upper band and sling swivel screw is No2BA, .64" long. Foresight protector and rear trigger gd screw are No.4 BA. Length of foresight protector screw is .84" or .92". Rear triggergd screw is 1.06". Proper head size/diameter is also an issue. I have these specs as well. You can google British Tools & Fasteners, LLC for generic info on thread dimensions. They are a source for British spec taps, dies, nuts, screws and bolts. I've bought a die from them to clean up No.4 striker threads.
gaff
04-28-2014
The trigger guards screw and foresight protector screw are 4BA not 2BA. The scope pad screws on the T are 4BA also.
stencollector
04-28-2014
Just to add misery, there was a different screw pitch for the bands for the no1mk3. But a later instruction for the military made them interchangeable by running a tap through the No.4 bands if I recall. We were getting the no1 screws in the late 90s in the CF as replacements for the No.4 rifles.
There is no easy substitute for the real thing. Check at the next gunshow, or else place an order with Sarco in the US, who will ship to Canada and seem to have the best prices. Some places will ding you up to $3 for the swivel screws. Since you may find yourself addicted to Enfields after just a couple tastes, you might as well make the order a good one and order all the screws by the dozen.
A quick check of the Canadian Forces supply manual for the No.4 303 shows 4BA for the trigger screw and the front sight screw. It lists 2BA for the swivel/band screws.
wheaty
04-28-2014
Who else but Enfield would have a 26 1/2 pitch... that is the pitch for the SMLE and earlier.
I have a set of custom taps and dies in 26 1/2 and don't ask what they cost and NO, they are not for loan.
A great number of screws from the UK are proprietorial to the maker. There are some funny threads out there.
The British even have a special thread for brass.
Anything in the No.4 is straight BA.
stencollector
04-28-2014
Originally Posted by wheaty
Anything in the No.4 is straight BA
...except for the two 1/4 BSF and the one 7/16 BSW. Both the striker and the front trigger guard screw (also referred to as the King Screw) are 1/4 BSF, and the butt stock bolt is 7/16 BSF. If the rifle is a T with the no32 scope bracket, then the rear hole in the body is also 1/4 BSF, as are both bracket knobs.
I have some of the special Enfield taps downstairs as well. Friends don't ask to borrow friends' Enfield taps and strangers need not apply.
smellie
04-29-2014
Enfield threads, many of them, were developed in the 1830s through to the 1860s.
They are "goofy" by modern standards because they don't interchange with what we use today.
Why should they? They were the FIRST standardised, fully-interchangeable system of threads in the world. If anything, the modern stuff should be compliant with THEM.
The system was nailed down by Sir Joseph Whitworth. He later used the Enfield threads as his starting-point when he designed his 55-degree round top/round bottom system of threads which is now called (in the fine threads) British Standard Fine and in the coarse threads, the British Standard Whitworth thread.
Lee-Enfield rifles up to and including Number 1 Mark VI use the Enfield thread system. Threads were changed on the Number 1 Mark VI from Enfield to British Association (BA) and the resulting rifle was called the NUMBER 4 Mark 1. BA is a fine thread on a metric shank; you should be able to get them from any shop specialising in model trains and such.
Number 1 Rifles will have screws with round "cheese" tops whereas the screws on the Number 4 have FLAT tops.
Working on "Enfield" rifles, it really helps to make clear exactly what you have.
burnt_servo
04-29-2014
I don't know if this helps anyone... but a couple years ago I was on ebay looking for some oddball taps, found one that was close but the thread pitch was off.
on a whim I emailed the guy (Chinese seller), and it was no problem to get exactly what I wanted (he ran his own machine shop). I got a 1 inch tap, 14 tpi with a 55 degree pitch for 20.00 shipped.
I thought it was a heck of a deal, and it only took just over 2 weeks to arrive.