way surfaces a feature which cannot be accomplished with metal gibs the material to be used in accordance with the present invention is a thermoplastic base material such as an acetal resin containing a ptfe lubricant which is finely divided and uniformly distributed through the acetal resin the ptfe is present in an amount sufficient to reduce the coefficient of friction of the acetal resin but not present in an amount which creates creep of cold flow of the compounded mixture as will be apparent from the data hereinafter set forth while ptfe has been included in the material and operates to reduce the coefficient of friction lubricating oils and the like may be used with the gib of the present invention the compounded material may be injection or extrusion molded and thereafter punched milled stamped drilled ground or machined to final dimensions if desired such a material being basically an acetal resin has outstanding creep resistance although the addition of the ptfe additive for lubricating purposes reduces it somewhat to assure dimensional stability of the material the parts are heat treated after formation to take out any stresses formed during molding the acetal resin may be a homopolymer or a copolymer and the compounded material with the ptfe offers the advantages of low moisture absorption i e between 0 15 and 0 25 percent after 24 hours and between 0 5 percent and 0 8 percent at an equilibrium condition when tested by astm d570 the flexural modulus as measured by astm d790 is relatively high i e between 350 000 and 410 000 psi the modulus of elasticity is also high and between 200 000 and 400 000 psi and preferably between 350 000 and 380 000 psi as measured by astm d790 the tensile strength is.