"Vice Hold Downs"

[Highpower]

Anybody use them?

I was skimming though ebay last week and a used pair of Starrett 54C vice hold downs caught my eye. They were on a "buy it now" with not much time left and I made a low ball offer figuring it would go nowhere. To my surprise the seller accepted my offer about 10 -15 minutes later.

They arrived in today's mail. If you have them - how often do you find yourself using them?

Or are they just a solution to a problem that doesn't exist? Just curious.

[EdK]

I had to ask for Mr Google's help with that. I've never heard of or seen such things.
They look scary to use to me but I'm a wuss, but a wuss with all digits intact.

Ed

[Dr Stan]

Gotta have someway to hold down non-ferrous material on a magnetic chuck.

[Highpower]

(11-14-2015, 04:05 PM)EdK Wrote: They look scary to use to me but I'm a wuss, but a wuss with all digits intact.  

Ed

I took a look at Mr. Google and see now what you are talking about Ed. Two pictures right out of the gate show the hold downs angled upward away from the base of the vice. Yeah, I can see where that wouldn't work out so well.

I bought a set of the Mighty-Bite fixture clamps for my mill table a long time ago. Unfortunately I didn't realize at that time that the type I bought did not provide any downward force to the part. I don't trust them.



I have seen similar types of hold downs as the 54's for magnetic chucks that have serrated cuts in the edges that compress against the work when they are pulled down by the magnet. Also seen that done in wood as well for preventing kick-back on table saws or joiners or something....

Sometimes I'm just leery of the "aspect ratio" of some parts, where you can only grab on 10% of the base of the part, and the other 90% is sticking up above the vice jaws. Kind of like holding a 12" piece of round stock in the lathe with 1 inch held in the jaws - and no tail stock. Somehow you just know something is going to go wrong.

That's why I'm wondering if these things really help - or not.....

[Dr Stan]

The 54's are designed to flex when the mag is turned on giving some downward force, something lacking when one only blocks in the part.  One still has to have the proper grinding wheel (typically silicone carbide abrasive, very soft bond and open structure) along with very light cuts and moderate step overs.  An extra pair of skivvies also helps.

[TomG]

Willie,

That type of hold down is meant to be used in a vise. The edge along the thick side has a bit of taper to it and forces the opposite edge down when clamped against a part. They work well, but take a lot of room in the vise, so their use is somewhat limited.

There is also a type meant for surface grinding that has a bunch of fingers along one edge. These are pushed against the edge of a part on a magnetic chuck and flex when the magnet comes on, forcing the part down. I've used them before for grinding aluminum parts, but they are very scary.

Tom

[Pete O]

I read through this thread and googled the Starrett 54C the other day, my education continues.
Yesterday I was going through a pile of stuff that I had earmarked for scrap, looking for some suitable packing for another project. I came across this thing, having thrown it in the pile a couple of weeks ago. I'm now wondering if this is a hold-down thingamajig, as it has similar edge geometry. It was amongst a ton of stuff I bought from a machine shop clearing sale, much of which I can't identify.
   
Can anyone confirm or deny?

[PixMan]

No idea what that is, but nothing like a Starrett No.54C, that I can assure you.

[Sunset Machine]

Could it be a cutting tool? It looks like a die from a threader.

[dallen]

it fits onto something because of the dovetail on the one side of it.