# PPI for backside of tapered gib?



## AndySomogyi (Apr 24, 2021)

What’s considered good enough PPI / coverage for the *backside* of a tapered gib?


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## Ulma Doctor (Apr 24, 2021)

15 to 20ppi would be sufficient


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## AndySomogyi (Apr 24, 2021)

Didn’t realize the back side should be that high. My coverage / contact area isn’t spectacular on the backside.


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## Ulma Doctor (Apr 25, 2021)

get what you can then!
if all you can muster is 10, then 10 is the magic number


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## Richard King 2 (Apr 25, 2021)

I teach 5 PPI.  It is a static surface and no need for more.  % is better the PPI.  60 to 80% is better.  Another trick you need todo is check the positive side that the gib rests against.  Check it with a dovetail straight-edge  to be sure it isn't high in the middle or burrs on the edges where the gib screw goes.  You not done yet.  blue up the surface were the front of the gib rides and rub the positive side against it and scrape the positive side to match fit that side so the width (top to bottom) .  This must be done. if not the gib won't be the same thickness if you measure the top to bottom of the gib.  Or co-planer.  If this happens as you slide the gib in and it is not co-plaer it could drop and tighten or loosen up and you will get false readings when checking the taper end to end.    I wish I could show in some photo's as it's a pain to try to type it.


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