Strong, stiff plastic with outstanding chemical resistance; performs over a wide range of temps PEEK (polyetheretherketone) is a high-performance engineering plastic with outstanding resistance to harsh chemicals Excellent mechanical strength and dimensional stability. Replacement for machined metals in a wide variety of high performance end-use applications. 5 Crosshead bolts, 5 x nuts Offers hydrolysis resistance to steam, water, and sea water. PEEK has the ability to maintain stiffness at high temperatures and is suitable for continuous use at temperatures up to 338oF (170oC). This engineering plastic has a proven track record in challenging environments such as aerospace, oil and gas, and semiconductor.