A bit of help needed

Myros

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do any of you engineering-minded types have access to a small lathe, or other suitable piece of kit capable of doing the work below?

I need to machine some 5/16ths hex-head bolts down to a countersunk, round finish, and machine a Phillips cross slot into them as well, and taper the other end so it becomes a pointy bit.

The countersink and taper angles look the same, at about 45 degrees, I'd guess.

On some others, I need to machine the hexhead to a round pan head and put a cross slot in that, and taper it as well at the other end.

Way beyond any kit or capability i possess. Surpassing my descriptive powers as well, by the looks of it.
 
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television

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The turning down is not a problem but cutting a cross head would be out of the question for most, is there not a better bolt that you can start off with
 
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Myros

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not that i have found yet Malcolm

I'm trying to find , or replicate, some 3/4 inch by 5/16th dia BSF pan head screws, and some 1 and 1/2 inch by 5/16th dia countersunk door hinge screws.

All for a chum abroad who is renovating his 1955 Jag. He can't find imperial stuff for love nor money.

I can find lots of bolts, but no screws. Unless any one her knows of a decent supply.

I could probably grind in the cross head with a dremel or similar, but I bet it won't look great.
 
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television

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I still have boxes of screws from jags I took apart years ago,, you never know what I might have
 

Frontstep

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Perish the thought but BL or MG ones could well be the same size its a bit long ago for me to remember.
 

television

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The common screws back then were unified and AF,, and I would say AF for this. Not many cars used BSF as the thread was a bit coarse for car use
 

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Hi i have just restored two tractors one 1959,the other a 1966 and there is a firm near me that seem to have every type of nut bolt screw that you can think of,as i have changed most of the bolt etc and all imperial they have even managed to supply most in stainless steel.
they are called danlett 01484 518798 they are ever so helpfull,a couple of the people who work there do classic cars and bikes
 

television

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Just as a footnote, the door hinge bolts had a point on the end to help center the floating plate in A and B pillars
 
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Myros

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Thank you all Gentlemen

plenty of food for thought there.

I've ordered the required quantity of bolts as a fall-back, and shall sally forth into the screwy world of nuts tomorrow.

Malcolm, if you want to offload your Jag bits and bats, I'm sure some of it would be useful to my mate. Probably all of it. He's ok, he has a 500SL as well.
 
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television

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plenty of food for thought there.

I've ordered the required quantity of bolts as a fall-back, and shall sally forth into the screwy world of nuts tomorrow.

Malcolm, if you want to offload your Jag bits and bats, I'm sure some of it would be useful to my mate. Probably all of it. He's ok, he has a 500SL as well.

I do not have that much left, I had a quick look in the box and I recognized some parts like the a bonnet spike that locks the bonnet down and some other screws with Jaguar blue paint on them, I might have the correct screws I will empty out the box in the morning :D.
 

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Are you sure they are BSF and not UNF, mid fifties is just about the right time for the big change to UNF and Jags market was the US, home of UNF.
The Phillips recess also of US origin was introduced to the UK about the same time, older cars used to have slotted screws in their hinges.
My 1955 big Healy 100M had a real mix of Whitworth and unified threads, hows about spring shackle pins with 3/8 UNF male one end and 3/8 BSF male at the other?

Cross head recesses are struck into the head with a punch, their geometry is (almost) impossible to accurately machine cut, none of the faces are parallel to the axis and the corners have too small a radius to be cut with end mills. A 4 axis CNC machine could do it if a form tool was used but at a small quantity price that no one would willingly pay, i.e. model blank, make blank screws, make fixture, programme machine, make cutting tool and then make some product which would not look exactly like a volume produced part by being too nice.
 
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Myros

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Thanks Wireman

I was basing it all from measurements I took with my vernier calipers ( I don't have a micrometer, what kind of fool am I?), and counting the tpi under a magnifying glass.
I got it to 22 tpi. I have just tried a nut from a 5/16 bolt i bought at the motor factors. It's a perfect fit, so UNF is much more likely than BSF.

It just shows that i shouldn't be let loose on a set of engineer's tables and any kind of measuring equipment.

I'll take the two samples i have along with me wherever I go to try and source them.
 
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television

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I have just check my stock,, but all the Xj6 used hex bolts for the door hinges with the point on the end

I have 6 of those still painted jag blue, but no roundheads at all :(
 
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Myros

Myros

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Thanks again Gents

all sorted now. Danletts had the short ones in stock, with an Allen socket head.
The long one wasproving to be a short straw everywhere, until my mechie inpsected it, and said it was just like a landy door-hinge screw. A quick trip to Steve Parker Land Rovers in Whitworth and job sorted.

Many hands make light work.
 


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