How many threads engaged

I always check the thread engagement at the shank since structural bolts have random thread lengths. If building machinery, use lock washers and flat washers on slots with grade 5 bolts, not A bolts. This is our practice. ASME B Any which fail to do so are considered acceptably engaged if the lack of complete engagement is not more than one thread.

I would think that this requirement is dependent on the nature of the objects being fastened together. Taylor — Yes, exactly. Every application will have its own nuances that may require more or less thread engagement.

Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. How much thread engagement is recommended, i. This in itself is not a serious deficiency as long as at least three quarters of the nut is engaged. The answer is: A minimum of two thread pitches should extend beyond the top surface of the nut.

The bolt length used shall be such that the end of the bolt extends beyond or is at least flush with the outer face of the nut when properly installed. A conservative estimate of the resulting nut strength can be made based on the percentage of threads engaged, as long as at least half of the threads in the nut are engaged.

Thanks for info.. Thank you for the assistance. Just a thought. Wow, this is in every respect what I needed to know. Leave a Reply Cancel reply Your email address will not be published. Leave this field empty. On the flip side, if there is not enough bolt length engaged in a nut member, the bolt has a higher probability of stripping out before full tensile strength capability is achieved. Depending on the strength of the nut material, you need at least One factor that affects this is the nut material.

Steel is a close to a Rules of Thumb for Thread Engagement. Field Fastener. Thread Tools Show Printable Version. Hello all, I'm building a small IC engine and was wondering about tapping small threads. Is this correct? General rule I have in my head is 1 diameter deep in steel and 2 diameters deep in aluminum. For most work, though, I hedge towards 2 dia in steel and 3 in aluminum if possible. Conventional wisdom is the bolt should fail before the tapped hole.

This preserves the part for a new bolt which is the cheapest fix. Look at standard nuts. They tend to be about a bolt diameter high and they never fail unless something disastrous happens.