Holding down clamps

[Peter Ellis 5Participant @peterellis5]

One for the Europeans. Does anyone have a source for holding down straps ? I can only find complete holding down sets. I'm talking of the sets in red stands. I'm looking for just the straps with the dog toothed ends that match the triangular raising blocks. The ones I have are only short and result in the bolt fouling the bottom of the raising block when used at full height, Pictures of complete sets seem to show much longer ones, but they never seem to be offered seperately. Ideally to suit 8mm bolts.

This is what I am looking for. There must be millions of these being made yet whatever description I try comes up with everything but !

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[Peter Ellis 5Participant @peterellis5]

[Martin ConnellyParticipant @martinconnelly55370]

Wixroyd and WDS come to mind but the cost may surprise you as they sell to industry.

Martin C

[not done it yetParticipant @notdoneityet]

Making your own should not be too difficult? It is where my extra clamping bars have come from – off my mill. About the best way to get them the size you actually need!

[JasonBModerator @jasonb]

MSC also do them but at about £10 a pop almost as cheap to buy a set and just use the bars out of that.

[Henry BrownParticipant @henrybrown95529]

Pop "used milling clamps" into ebay, there are a few sets on there…

[DC31kParticipant @dc31k]

This one from Zoro is reasonably priced:

https://www.zoro.co.uk/shop/spindle-nose-and-workholding/clamping-components/sc105225-55-x-25-x-12mm-m10-step-clamp/p/ZT1125807X

[Peter Ellis 5Participant @peterellis5]

Posted by not done it yet on 01/02/2023 15:41:58:

Making your own should not be too difficult? It is where my extra clamping bars have come from – off my mill. About the best way to get them the size you actually need!

I thought of that but didn't fancy doing the serrated ends.

Cheers

Peter

[Peter Ellis 5Participant @peterellis5]

Posted by Henry Brown on 01/02/2023 16:05:13:

Pop "used milling clamps" into ebay, there are a few sets on there…

I had a shufti there but couldn't find what I wanted. Prices seemed optimistic. $175 for a kant clamp for instance, I've just made a pair for 25 quid which was mostly paying for a firm to water cut the frames.

[Peter Ellis 5Participant @peterellis5]

Posted by JasonB on 01/02/2023 15:47:20:

MSC also do them but at about £10 a pop almost as cheap to buy a set and just use the bars out of that.

I thought of that, too. Flogging the rest seperately on eBay could recover the cost of the bits I keep !

[Peter Ellis 5Participant @peterellis5]

Posted by DC31k on 01/02/2023 18:04:21:

This one from Zoro is reasonably priced:

https://www.zoro.co.uk/shop/spindle-nose-and-workholding/clamping-components/sc105225-55-x-25-x-12mm-m10-step-clamp/p/ZT1125807X

,Thank you ! Those are more like it. Not the bolt size but I can work around that.

Cheers

Peter

[Rod RenshawParticipant @rodrenshaw28584]

There was a hint in one of the Mags (MEW? ) recently suggesting milling a slot out of the centre of the width of the low end of the triangular riser blocks to avoid/ reduce the tendency for the clamp bolt and the riser to foul each other.

[Clive FosterParticipant @clivefoster55965]

Peter

Alternative to buying would be to make tapped end ones to take a bolt size of your choice. Tapped hole is much easier than steps.

Like these from the Zoro site

**LINK**

https://www.zoro.co.uk/shop/spindle-nose-and-workholding/clamping-components/cc06-tapped-end-plain-clamp/f/3075

Need a washer to protect the table or fit a soft end and run down inside the table tee slots. I've always found the step blocks somewhat cumbersome and, in the case of my Bridgeport, a bit narrow as they are barely wide enough to span the table slots so the straps are best placed at an angle. Which is frequently inconvenient.

One day I will be sufficiently annoyed to make a batch!

Clive

[JasonBModerator @jasonb]

If the problem is simply the triangular block hitting the stud/bolt then just stand the triangle on a bock of something which will raise it up and therefore away from the stud

Edited By JasonB on 01/02/2023 19:23:57

[Peter Ellis 5Participant @peterellis5]

Posted by Rod Renshaw on 01/02/2023 18:39:56:

There was a hint in one of the Mags (MEW? ) recently suggesting milling a slot out of the centre of the width of the low end of the triangular riser blocks to avoid/ reduce the tendency for the clamp bolt and the riser to foul each other.

That's an interesting idea.

Cheers

Peter

[Clive FosterParticipant @clivefoster55965]

Correct practice is to have the stud close to the piece being held down so the triangular block shouldn't be close enough to the stud to interfere with it.

As Jason says use a raising block if need be.

Generally such interference indicates that the set up is iffy so clamping forces may prove inadequate.

For our sizes of work a simple flat bar resting on one step will be sufficiently secure unless the job is very thin in which case the block may tilt due to the offset loading. Leaving aside the slight undercut on the steps that makes it easier to slide the block and strap assembly around without disconnection there seems no overwhelming engineering reason for the multiple steps. Engaging on only one step should be amply strong enough to fracture a Tee slot or snap a stud if you use really long spanner.

Putting the appropriate undercut on a single step if making your own clamp bars is easy enough. Judging by my set great angular accuracy is not needed.

Clive

[Nigel Graham 2Participant @nigelgraham2]

I've made effective clamp bars by bolting two strips of black mild steel together at their ends and centrally, with stud-clearance width spacers between them. They could use a clearance hole in one and tapped in the other.

Note that the bars should be rectangular section and assembled wide sides vertically, for stiffness.

They do not sit on the steps but on plain blocks, or pairs of stepped blocks engaging each other to give flat clamp seats. Nor would I rely on using a single step.

I've also augmented my clamp-set, of the type in you original photo, with two sets at different lengths of 3/8" UNC bolts having ascertained that is the right thread. I put large washers under the bolt heads.This often allows a much more compact set-up than using the normal studs and flanged-nuts.

It's worth too making some T-nuts with much smaller, e.g. 1/4" or M6, threads, to assist clamping small work-pieces with suitable holes through them by nature. Ensure the screw cannot wind right through the nut.

[Peter Ellis 5Participant @peterellis5]

Thank you for the thought provoking ideas. It seems Chronos do a complete set for 40 quid including postage !

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