The shim is then formed to include {HEAD ~ a feature} on {TAIL ~ its surface} which complements the surface profile of the assembly surface 
on
The shim is then formed to include { HEAD ~ a feature } on { TAIL ~ its surface } which complements the surface profile of the assembly surface
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH