Tag: A286 screws for high strength

A286 Bolts for Diesel Engine Exhaust Stream

Q:  Looking for bolts that will be used for large Diesel engine exhaust compensators in a power plant. The normal operating temp of the exhaust is 700 degrees F at full load. Loads do fluctuate often and engines experience downtime. The exhaust system does experience extreme force and vibration. Any suggestions?

A:  It sounds like a safe bet would be A286 bolts. This material is geared for high temperature exhaust streams and will do well in this kind of environment. A286 is an age hardened material that can retain its strength to 1300°F. They also offer oxidation resistance to 1500°F . A286 fasteners offer 130ksi UTS and of 85ksi yield strength.

Age Hardened 17-4PH and A286 Bolts: Strength & Ductility

Q:
An application with limited space using a #4-40 screw with an assumed tensile strength of 120,000 PSI. This screw continues to break. Do you offer a screw with a higher strength? Also, This screw is used to hold a plate to the end of an air cylinder.  It probably jars the fastener on every stroke and has about 6-8 strokes per minute.
A:
Regarding materials, there is a whole range of materials stronger than 120 ksi UTS however it sounds like you not only need strength but also a material that is ductile.  I would suggest looking at fasteners made from the age hardened stainless steels such as  A286 or 17-4 PH. Known for its high temperature oxidation resistance, A286 bolts also offer excellent high strength capabilities. A286 typically offers a min of 130ksi UTS and 85 yield. 17-4 PH bolting offers varies levels of strength depending on the age hardening process used ranging from 145ksi to 200ksi UTS (H1150 and H900 respectively). Given your application has a repetitive jarring motion you should look at the 17-4 H1150 or the A286 per ASTM A453, 660 A, B or C.   These heat treat conditions will give you much more strength but also leave you with a material that is ductile and not brittle which may be a big factor in your fastener application.