Method For Calculating Bolt Lengths

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Method For Calculating Bolt Lengths

"F" Values

Flanged Joint Class	Total Height of Facings or Depth of Ring - Joint Groove for Both Flanges F
	Type of Flange Facing
	0.06 in.	0.25 in	M & F T & G	Ring - Joint

150, 300 & 600

Zero²0.12 in.

0.50 in.
0.50 in.

0.25 in.
0.25 in.

2 X groove depth
2 X groove depth

Raised face (0.06") is included in minimum flange thickness for Class 150 and 300 flanges.

"n" Values

Length

Negative Tolerance on Bolt Lengths
"n"

A
or
(A + (pipe thickness for each lap)
or
(A - F + (Table C Thickness)

0.06 in., for lengths up to 12 in. incl
0.12 in., for lengths over 12 in. to 18 in. included
0.25 in., for lengths over 18 in.

B
or
(B + (pipe thickness for each lap)
or
(B - F + (Table C Thickness)

For "n" values
use negative length tolerances
per ANSI B18.2.1.

Thickness for Lap-Joint

Lap Combination

150 & 300 Flanges

Class 600 Flanges

For lapped to 0.06 in. Raised Face	One Lap	.................................
For Lapped to Lapped	Both Laps	Both Laps
For Lapped to 0.25 in. Male Face on Flange	.................................	One Lap and 0.25 in.
For Lapped to Female Face on Flange	.................................	One Lap not less than 0.25 in.
For Male in Lap to Female in Lap	.................................	2 X pipe wall with Lap for Male not less than 0.25 in.