Thread: Stripping Hex Head Socket Screw

Originally Posted by Dibbers

Is stainless the way to go?

No - even more chance of stripping/snapping. When I put SS screws into timber I first pre-drill the drilled hole with a same-size steel screw.

You probably don't want the new screw to be any harder (or of course softer) than the female thread it's going into, otherwise in a moment of exuberance you may strip the female thread and that would be very problematic. Others will probably know best, but I would think just a normal, but good quality, screw would be best. Can't help on where to get one, but maybe search for Grub Screws or Machine Screws.

Dibs, do you mean the screw thread has stripped or the internal hex drive has stripped? Unbrako is the best brand and can be obtained from any specialist fastener supplier. It is quite common for the internal hex to strip if the key size is 3mm or under and don't use the ball type keys as they are not meant for final tightening only doing up in awkward situations and use a straight key to finally tighten if possible. On larger sizes they are reasonable but not small ones. Consider star (Torx) drive for the smaller sizes as it is far more reliable.

Yep its the internal Hex that strips (the bit you put the allen key into).

I'll look at the Star drive and see what options there are... I was considering trying to get an index fastener but not sure if the handle will hit anything on the scroll saw that'd render it useless...

Thanks for the advice, i'll have a look around.

Use Unbrako 12-point head fasteners as a replacement for the stripped Allen Head fastener. You need a minimum of Grade 8 (Imperial) or Grade 10.9 (Metric) to ensure high tensile strength.
Contrary to many peoples beliefs, stainless fasteners are not as strong (as regards tensile strength) as people tend to think.
The strongest fasteners are made from medium carbon, low-alloy steel with chrome, nickel, boron, and molybdenum additives. Unbrako specialise in extremely high-strength fasteners.
Stainless fasteners are best used where corrosion is major problem, such as in marine environments.

Originally Posted by onetrack

Use Unbrako 12-point head fasteners as a replacement for the stripped Allen Head fastener. You need a minimum of Grade 8 (Imperial) or Grade 10.9 (Metric) to ensure high tensile strength.
The strongest fasteners are made from medium carbon, low-alloy steel with chrome, nickel, boron, and molybdenum additives. Unbrako specialise in extremely high-strength fasteners.

Originally Posted by FenceFurniture

Others will probably know best

Yup

Does the screw bite down directly onto the blade?
If so then a harder material will not bite as far or hold as well as a softer steel and so then you will have to tighten the screw more.
If the screw is made too hard a material then there's a chance you might end up buggering up the internal thread of what you are repeatedly screwing into.
In this situation I have sometimes just bought a packet of the same hardness screw and just replace it every so often.

As Chris suggested, stick to a specialist fastener supplier as they won't have soft rubbish and there are a number of reputable brands of high tensile bolts and capscrews. Make sure you don't buy button head capscrews as the hex in them is smaller than a normal capscrew and can strip fairly easily, even the good brands.
Just make sure the hex doesn't have anything in it and before you put the Allen key in. Insert the key all the way, not just get it started and then start turning. For what you are doing with the blade clamp I would suggest using a Tee wrench as that will get you well clear of the saw and you will easily be able to see if you are in line with the screw so you won't put any sideways pressure on as you tighten/loosen the screw. Buying a single size Tee Wrench might be difficult as they normally come in sets, but you might be lucky somewhere. Again, buy good quality as both the key and screw need to be tough.

Originally Posted by BobL

Does the screw bite down directly onto the blade?
If so then a harder material will not bite as far or hold as well as a softer steel and so then you will have to tighten the screw more.
If the screw is made too hard a material then there's a chance you might end up buggering up the internal thread of what you are repeatedly screwing into.
In this situation I have sometimes just bought a packet of the same hardness screw and just replace it every so often.

I fully agree with BobL. It is much cheaper to replace soft screws regularly than it is to replace the part that they screw into.

It also may be the reason why the manufacturer has used a soft screw in the first place.

Thanks for the advice everyone.

I've got the new clamps on their way, and if they have the same issue i'll just buy a bunch of screws...

From what i can gather, the screw doesn't bite the blade, it closes the clamps around the blade.

The replacement clamps weren't costly, although are taking a while to get to me (from UK to Aus was quick, from the Aus Post Parcel centre 2 suburbs over, 1 week and counting...)

I'll switch out the clamps (which come with new screws!!!) and see if there's any improvement there... and i'll go looking for spare socket set screws.

@Treecycle, i was looking at getting a T-Handle wrench... haven't pulled the trigger on one yet, but will be easier on my hands than the allen key!

I have used literally thousands of hex drive (Unbrako) and the one golden rule is do not use ball drive keys to tighten at all, they only cause problems and stripped internals and 3mm is problematical no matter what the key so do not buy a key with a ball end or if you need one for a difficult spot buy two, one with and one without. The cross T that sticks out of the side of the T handle are difficult to use also in most circumstances and only good for undoing stubborn fasteners. If you have a stripped drive in a hex fastener the quickest and best way to get it out is drive an oversize torx or star drive bit into it with a hammer and it comes out every time.

Originally Posted by Chris Parks

I have used literally thousands of hex drive (Unbrako) and the one golden rule is do not use ball drive keys to tighten at all, they only cause problems and stripped internals and 3mm is problematical no matter what the key so do not buy a key with a ball end or if you need one for a difficult spot buy two, one with and one without. The cross T that sticks out of the side of the T handle are difficult to use also in most circumstances and only good for undoing stubborn fasteners. If you have a stripped drive in a hex fastener the quickest and best way to get it out is drive an oversize torx or star drive bit into it with a hammer and it comes out every time.

The stripped hex screw can be removed. I didn't know it was stripped when i went to tighten it so wouldn't tighten much at all, i was able to remove with pliers.

I was going to get the T-handle for when i replace the screw to use in future as the standard allen key is a bit of a pain...

As for the Torx screws, i can't seem to find them in the size i need... or in smaller quantities... I've only been looking online as i have a desk job and lots of time on my hands lol

Have you still got the Jet you mentioned on one of your other threads and if so is the blade clamp like the one below?

Mount.JPG

Don't waste your time trying to find them, just go into a specialist supplier such as Coventry fasteners (no endorsement) and take the original with you and ask them to supply it with star drive. That way you will be getting a quality fastener not a screw made from used beer cans. If you are in southern Sydney I can recommend Southern Fasteners in Kirrawee.

Originally Posted by Treecycle

Have you still got the Jet you mentioned on one of your other threads and if so is the blade clamp like the one below?

Mount.JPG

Yep, thats the one ive got. Ive ordered some replacement clamps from axminster that im waiting for. Will sand the inside of them as i believe theres a few people who have had a similar issue to me and this was a solution that worked for them

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