40% Bronze Filled PTFE Tubes Materials: Bronze + PTFE (Teflon) Method: Press ... can be made according to customers' request, for example 5% / 20% / 40%, etc.Bronze Filled PTFE (Teflon) Sleeves / Tubes, are manufactured by ... strength;Improved thermal conductivity;Decreased thermal expansion;Improved abrasion resistance. 40% Bronze Filled PTFE Tubes, by moulding