Thread Terminology (PDF)

Major Diameter - It is the largest diameter of the thread which would touch the crests.

Minor Diameter - It is the smallest diameter of the thread which would touch the roots.

Pitch Diameter - It is a middle diameter between the major and minor diameter of screw threads.

Root - Root of the deepest part of the grove that corresponds with the minor diameter.

Flank Angle -This is the angle made by the intersection of the two thread flanks.

Pitch - Pitch of a thread is the distance between 2 crests.

Angle - The thread angle of a screw is the angle between the threads.

Crest - Crest of the thread is the top part of the grove that corresponds with the majr diameter.

Flank - The flank is the angle at which the helix is raised to form a crest.

Updated: 8/6/2020

About Monroe


Over 60 years of manufacturing experience to best serve our customers



Monroe provides custom manufacturing solutions to clients throughout the world


Value Adds

Our knowledge, customer service & processes are structured to reduce delivery times, improve quality & cut costs



Monroe is committed to customer satisfaction, we strive for continuous improvement in our products and our people.


The information contained in this website is for general information purposes only. The information is provided by Monroe Engineering, LLC, Inc. (Monroe) and while we endeavour to keep the information up-to-date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk. All users should evaluate product suitability for each intended application of that product under actual use conditions. In no event will we be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from this information.

Are you looking for an RFQ?