A3 Specifying Miscellaneous Requirements: A3.1 Surface Roughness Call Outs: If required, surface roughness of welds shall be called out in the notes as follows: “SURFACE ROUGHNESS (RA) OF WELD SHALL BE NO GREATER THAN (specified value) MICRO-INCH AS DETERMINED WITH ANSI B46.1.”A3.2 Vacuum integrity: If required, vacuum integrity shall be called-out as follows: “LEAK-CHECK TO LEAK RATE NO GREATER THAN (specified value) STD-CC/SEC PER APPLIED MAERIALS SPECIFICATION 0250-20001.”A3.3 Filler metal: This specification does not cover the use of filler metals for welds exposed to vacuum. For structural welds where filler metal is required, the requirement shall be called-out as follows: “USE (specified filler type) FILLER METAL FOR INDICATED STRUCTURAL WELD”