NAS1057 Sleeve Spacers

NAS1057 is a National Aerospace Standard published by the Aerospace Industries Association (AIA) under the title "Spacer, Sleeve, Screw and Bolt, High Temperature, Non Magnetic." The parts are round sleeves that fit over a screw or bolt to hold a set distance between parts. The standard covers 18 sizes, for screw and bolt diameters from .112 in (size 0) up to 1.000 in (size 16), with lengths called out in .010 in steps and held to ±.005 in. Every part must have a magnetic permeability below 2.0 at a field strength of 200 oersteds, tested per ASTM A342 Method 3. Parts are marked with a recessed material code letter. Emanon quotes NAS1057 spacers with CofC and lot traceability, and quotes usually come back in about an hour.

HOW TO READ A NAS1057 PART NUMBER

A NAS1057 part number has four pieces: the basic number, a material code letter, a size code and a three-digit length dash number. Take NAS1057T4-075. • NAS1057: the basic standard number. • T: material code for CRES 303, 303 Se or 304, annealed. W is A286 CRES and X is X750 nickel base alloy. • 4: size code for a .2500 in screw or bolt. Size 4 has an inside diameter of .256 to .263 in and an outside diameter of .365 to .385 in. • 075: length in .010 in steps, so 0.750 in long, ±.005 in. Some size codes carry an A or B suffix, such as 3A, 3B and 4A. These keep the inside diameter of the base size but have a different outside diameter. Size 3B, for example, has an outside diameter of .490 to .510 in, against .302 to .322 in for size 3.

MATERIALS AND FINISHES

The material code letter sets the alloy. T parts are CRES 303 (ASTM A581 or A582), 303 Se (ASTM A511) or 304 (ASTM A269), all annealed, with a temperature limit of 800°F. W parts are A286 CRES per AMS5731, rated to 1200°F. X parts are X750 nickel base alloy per AMS5668, rated to 1500°F. Unless otherwise specified, the 303, 303 Se, 304 and A286 parts are passivated per AMS2700, Method 1, Class 4, and all dimensions apply after finish. Emanon's current NAS1057 list covers T and W parts.

SUPERSEDING SPECIFICATION

NAS1057 is active at Revision 10, dated November 21, 2014, and has not been superseded or cancelled. Per the standard, parts made to earlier revisions may still be procured and used until existing inventory is used up.