Installing vise - lag screws or bolts?

[secutanudu]

I have a workbench done, aside from vises and dogholes. It's a 3" top made of doug fir. I have a Wilton 10" vise that will be my front vise. I'd prefer not to have holes drilled all the way through, so would two 2.5" lag screws be enough to hold it long-term?

Or should I bite the bullet and just use bolts?

My other thought was to mount the vise to a larger block of wood (using bolts) then use 4 lag screws to attach that to the benchtop.

Thoughts?

Thanks!

[TimV]

Are you talking about underneath or through the rear jaw?

Underneath, I used lag bolts and into the face I used appropriately sized countersunk screws.

[Trip]

spax is a better choice over lag screws...

[Cochese]

I've used both, and the bolts are the way to go.

[secutanudu]

I'm talking about underneath. The bench is about 2-7/8" thick.

I would prefer screws, since they wouldn't show from the top. But I am worried about them becoming loose over time.

I'd also put some countersunk screws in the face of the vise.

[Dave H]

How about a pic of the vice it's hard to visulize you problem maybe that will make it clearer. Does the vice have any paper work/ directions or is it second hand?

[Dave H]

The end vice on my bench I used lags to hold it underneath seems to have worked out OK for me.

[rmac]

I say put the screws in because that's what you want to do. If they stay tight, you're in good shape. If they don't, then replace them with bolts.

-- Russ

[secutanudu]

This is the vise (not mine, a pic of the same model I found online). it was second-hand, so I have no instructions.

[JayWC]

I say put the screws in because that's what you want to do. If they stay tight, you're in good shape. If they don't, then replace them with bolts.

-- Russ

I'm in with Russ's comment. Try the screws first if that's what you want to do. Even thru-bolts can loosen as the top moves with humidity changes.

[man of wood]

Mount with lags, as long as your pre drill. Yes you don't want to wreck the top

[TimV]

I would prefer screws, since they wouldn't show from the top. But I am worried about them becoming loose over time.

Andy,

Lag bolts are not through bolts. They are pointed on the end like a screw but have a very large coarse thread and require a socket or wrench to tighten. As MOW mentioned, pre-drill the to match the shank size on the lag bolts. They will not loosen over time.

But, you can use screws if you want too. Just make sure you drive the screws in the back face first so that sits tight against the end of your bench then drive the screws underneath.