Xometry’s standards for threads apply to any internal or external threads for metal fabricated parts. Additionally, this is applicable to machined threads regardless of cutting method (e.g. cut, milled, rolled). This standard is intended to supplement the part drawing in order to help illustrate and define quality specifications that may not easily be communicated in a drawing.
Xometry’s Standard for Threads
- Threads should be fully formed and cut to specified size and class according to provided drawing.
- Threads shall be free of defects, notable damage, and contamination.
- Threads should accept the Go thread gauge and/or accept the No-Go thread gauge at least three (3) turns.
Carefully review drawing specifications and fabricate the threads to communicated standards. Take care to avoid significant thread damage and contamination. This may cause the thread to be non-functional and will impact mating parts. If constructed threads do not meet the workmanship standards here, the part should be remade or reworked before shipping to the customer. Contact Xometry’s Case Management team with any concerns by selecting “report an issue” in the portal for the job in question.
Meets Xometry's Quality Standard
All threads should be fully formed and cut to the correct size and class specifications as called out in the drawing. Threads shall be free of tears, cracks, foreign object debris, and any other notable damage or contamination.
Minor nicks, dents, or scrapes on threads are permissible and are not the reason for quality rejections unless the thread does not pass Go/No-Go thread gauge inspection. Threads should accept the Go thread gauge and/or accept the No-Go thread gauge at least three (3) turns.
Does Not Meet Xometry's Quality Standard
The example above does not meet Xometry’s Thread Standards. Threads shall be adequately protected to prevent corrosion. Corroded, rusted, or excessively oxidized threads are unacceptable and can lead to decreased fastener strength, incorrect torque values, and overall quality appearance below standard.
Dirt, grease, chips, and other contamination in threads are not permissible and can lead to poor assembly, contamination of the hydraulic system, or improper torque values.
Threads that are cross-threaded are unacceptable. They can prevent future thread engagement and can lead to decreased fastener strength, incorrect torque values, and overall quality appearance below standard.
Rolled threads that are not properly formed are not permissible. This can lead to larger than the specified minor diameter, lower thread strength, and could lead to miss-threading the fastener.