Sp r108

[Zung]

I bought a box of 4-40 ss allen head from a fastener store, but I didn't have a reg with me. The head turned out to be a little too large and the length a bit too long....so what length is best?

Thanks,

Couv

Bro, the ones I have are 7/16" or 11.00 mm as measured.
What's the size of the socket you have? Mine is weird, smaller than 3/32 and bigger than 5/64.

Edit
The head of my screw has a diameter of 4.22 mm or .166", and the hole in the clamp is 4.32 or .170". The McMaster Fillister head has a diameter of .183" or 4.65 mm and will not fit my clamp without some grinding.

 

[knowone]

With progress (attempts to demolish history and the slackening of tolerances)
and also the ageing of rubber, face to face becomes the tolerable space to space.

Evenly.

 

[Zung]

Same here: my working unit has spaces of about 1.5 - 2 mm.

 

[Couv]

couv,
What length did you try, 1/2" ? I was able to find (pretty easily) stainless 4-40's with a flat phillips head. I'm trying to use awap's suggested dremmel tool approach to get the screw heads recessed into the retainer bands....

Yes, they are hex key (allen) heads. 1/2" length. This thread forced me back to the work table for another look. I think I can live with the small amount of over length, but the heads have an appointment with the grinder.

Bro, the ones I have are 7/16" or 11.00 mm as measured.
What's the size of the socket you have? Mine is weird, smaller than 3/32 and bigger than 5/64.

Edit
The head of my screw has a diameter of 4.22 mm or .166", and the hole in the clamp is 4.32 or .170". The McMaster Fillister head has a diameter of .183" or 4.65 mm and will not fit my clamp without some grinding.

1/2 in length, the allen head I'm guessing is a 3/32...but not a perfect fit. The closest mm would be 2.5 but I haven't tried one.

Same here: my working unit has spaces of about 1.5 - 2 mm.

There are plenty of " v band clamps" in aviation. They are called v band clamps because of the cross section. The secret to installing a v band clamp correctly is to torque them down (both screws evenly) until you feel just a little resistance. Then tap on the band clamp in several places (ball peen hammer in aviation-wood table or hard plastic screwdriver for a regulator) re-torque and keep repeating until you are satisfied with the fit and feel of the torque.

I'm thinking Master Awap's K-Y Jelly might be of some use here too to reduce friction between the case and clamp.

 

[Zung]

Ouch! Hammering shut that piece of national treasure is a heresy!
I've got report from reliable source that Master awap uses it to drive nails, but then he's the Master.