// TECHNICAL RESOURCES
MS51957 pan head machine screws.
A purchasing guide to corrosion-resistant steel, cross-recessed machine screws with UNC-2A threads. Identify the series and send Webson the complete requirement.
// DIMENSION GUIDE
Machine-screw length and thread diameter
Schematic only; not to scale. Letter labels are keys for this illustration. Use the applicable part specification for dimensions, tolerances and measurement conventions.
// SERIES OVERVIEW
What is an MS51957 screw?
MS51957 identifies pan head, cross-recessed machine screws in corrosion-resistant steel with UNC-2A threads. It is a specification-controlled family: the complete designation and the applicable drawing define the item required for an assembly.
The series is commonly described as stainless pan head machine screws. For purchasing, retain the exact MS number and all suffixes rather than substituting a generic commercial description.
// IDENTIFICATION
MS51957 at a glance
| Characteristic | Reference information |
|---|---|
| Head style | Pan head |
| Drive description | Cross-recessed |
| Material family | Corrosion-resistant steel |
| Thread designation | UNC-2A |
| Document status | Active, checked October 17, 2026 |
| Document revision reviewed | Revision G, dated April 14, 2025 |
// PART NUMBERS
How to read the ordering requirement
Start with the complete designation on the drawing. The series number alone does not identify a single screw size. Use the part-number tables in the required issue of MS51957 to establish the selected diameter, length and any applicable suffix requirements.
Dash-number systems differ between series. Do not infer a length or material from a similar-looking MS or NAS number, and do not add or remove a finish suffix without checking the specification.
// RELATED SERIES
MS51957 and MS35206
Both series are associated with pan head, cross-recessed machine screws, but their stated material families differ. MS51957 covers corrosion-resistant steel; the MS35206 series description identifies cadmium-plated carbon steel with UNC-2A threads.
The MS35206 document review also identifies NASM35206 as its successor. Shared head and thread descriptions do not make these series interchangeable.
See documented specification relationships →// QUOTATION
What to include in your MS51957 RFQ
- Complete MS51957 designation, including dash number and suffixes.
- Quantity and required delivery date.
- Drawing or specified revision, when applicable.
- Any additional finish, inspection or testing requirements.
- Required certificate of conformance, manufacturer documentation or lot traceability.
Webson reviews specification-controlled hardware requirements for quotation. Availability and documentation depend on the complete part number, source and order requirements.
// FREQUENT QUESTIONS
MS51957 questions
Has MS51957 been replaced by NASM51957?
The document review completed on October 17, 2026 lists MS51957 as active. This guide does not assert a NASM51957 replacement.
Can I order using only the series number?
Provide the complete designation to identify the required size and variant. If the designation is incomplete, send the drawing or specification for review.
Does this page confirm inventory?
No. Submit the full part number and quantity to receive pricing, availability and documentation details.
// SOURCE WITH WEBSON
Have a part number or bill of material?
Send the complete designation, quantity, required delivery date and documentation requirements. Webson will review your requirement for quotation.