There are some very good double-sided tapes available these days

MichaelG.

Pattex branded cyanoacrylate (superglue) worked fine for me when I put magnets into the aluminium soft jaw covers I use on my big Record vice. Magnets came from a LiDL "40 pack" and were recessed into the alloy. Cleaned before sticking but not abraded.

I have my doubts about Pinkgrip. Instructions say one surface should be porous. My experience is that sticking metal or similar impermeable substance on to wood or similar surfaces results in far longer drying times, up to 2 days, than sticking to porous surfaces together.

Clive

.

Sounds an attractive option

MichaelG.

JBWeld would be attractive if it's going to get hot or come into contact with fuel

The tachometer magnets on my lathe spindle sit in a flat bottomed shallow recess. Whilst the magnets are more than powerful enough to stay on the spindle at 2500 rpm. the recess lip is needed to stop them sliding. No adhesive needed.

As Magnets and glue are both weak in shear, a physical restraint is best, not glue. Only needs a shallow lip.

Dave

Watch the roughing up, Neodymium is very prone to rust hence the plating on them.

as most news are nickel plated a lot of glues don't grip too well what I have done in the past is to bore a close fitting recess and fit the magnet then distort the edges slightly as the mags have slightly rounded edges.