Tapping

ACP supports standard UNC, UNF, and metric internal threads in through and blind tapped holes. Blind holes require a clear thread depth callout.

Required drawing callout

• Thread size and pitch.
• Through or blind.
• Thread depth for blind holes.
• Quantity when multiple tapped holes are required.

Drawing callout examples

• 1/4-20 UNC-2B THRU
• 10-32 UNF-2B x 0.375 DP
• M6 x 1.0 - 6H THRU
• M8 x 1.25 - 6H x 12 mm DP

Common standard inch tap sizes

#4-40, #6-32, #8-32, #10-24, #10-32, 1/4-20, 1/4-28, 5/16-18, 5/16-24, 3/8-16, 3/8-24, 1/2-13, 1/2-20, and 3/4-10.

Standard metric tap sizes

Common shop standard sizes: M3 x 0.5, M4 x 0.7, M5 x 0.8, M6 x 1.0, M8 x 1.25, M10 x 1.5, and M12 x 1.75.

• If a blind hole thread depth is not shown, ACP will request clarification before production.
• For critical thread fit, specify the inch thread class or metric tolerance and any required gaging.
• Threads not listed above can be reviewed through a custom quote.
• Only tapping explicitly listed in the quote is included.