Dimensional Tolerances per ASTM B251

Wall Thickness Tolerances for Copper and Brass Tube (Applicable to Specifications B 68, B 75, and B 135.) Note --- Maximum Deviation at Any Point: The following tolerances are plus and minus; if tolerances all plus or all minus are desired, double the values given.
Wall Thickness, in.	Outside Diameter, in. A
	1/32 to 1/8, incl.	Over 1/8 to 5/8, incl.	Over 5/8 to 1, incl.	Over 1 to 2, incl.	Over 2 to 4, incl.	Over 4 to 7, incl.	Over 7 to 10, incl.
Up to 0.017, incl. Over 0.017 to 0.024, incl. Over 0.024 to 0.034, incl. Over 0.034 to 0.057, incl. Over 0.057 to 0.082, incl. Over 0.082 to 0.119, incl. Over 0.119 to 0.164, incl. Over 0.164 to 0.219, incl. Over 0.219 to 0.283, incl. Over 0.283 to 0.379, incl. Over 0.379	0.002 0.003 0.003 0.003 --- --- --- --- --- --- ---	0.001 0.002   0.0025 0.003   0.0035 0.004 0.005 0.007 --- --- ---	0.0015 0.002   0.0025   0.0035 0.004 0.005 0.006   0.0075 0.009 0.012 ---	0.002   0.0025 0.003   0.0035 0.004 0.005 0.006 0.008 0.010 5B% 5B%	--- --- 0.004 0.005 0.006 0.007 0.008 0.010 0.012 5B% 5B%	--- --- --- 0.007 0.008 0.009 0.010 0.012 0.014 6B% 6B%	--- --- --- --- 0.010 0.011 0.012 0.014 0.016 6B% 6B%

Average Diameter* Tolerances for Copper and Brass TubeA (Applicable to Specifications B 68, B 75, and B 135.) Specified Diameter, in. Tolerance, plus and minus, in. Up to 1/8, incl. Over 1/8 to 5/8, incl. Over 5/8 to 1, incl. Over 1 to 2, incl. Over 2 to 3, incl. Over 3 to 4, incl. Over 4 to 5, incl. Over 5 to 6, incl. Over 6 to 8, incl. Over 8 to 10, incl. 0.002 0.002   0.0025 0.003 0.004 0.005 0.006 0.007 0.008 0.010

Straightness Tolerances for Copper and Brass TubeAin Any Drawn Temper (Applicable to Specifications B 75, B 135, and B 466.) Note --- Applies to round tube in any drawn temper from 1/4 (6.35 mm) to 3 1/2 in. (88.9 mm), incl. in outside diameter. Length, ft.B Maximum Curvature (Depth of Arc), in. Over 3 to 6, incl. Over 6 to 8, incl. Over 8 to 10, incl. 3/16 5/16 1/2

Length Tolerances for Copper and Brass Tube, Straight Lengths (Applicable to Specifications B 68, B 75, and B 135, B 466.) Note --- Tolerances are all plus; if all minus tolerances are desired, use the same values; if tolerance plus and minus are desired, halve the values given.
Length	Tolerances, in. Applicable only to Full-Length Pieces
	For Major Outside Dimensions up to 1 in. incl.	For Major Outside Dimensions over 1 in. to 4 in. incl.	For Major Outside Dimensions over 4 in.
Specific Lengths:   Up to 6 in., incl.   Over 6 in. to 2 ft., incl.   Over 2 ft. to 6 ft., incl.   Over 6 ft. to 14 ft., incl.   Over 14 ft.	1/32 1/16 3/32 1/4 1/2	1/16 3/32 1/8 1/4 1/2	--- 1/8 1/4 1/4 1/2

*The average outside or inside diameter of a tube is the average of the maximum and minimum outside diameters, or of the maximum and minimum inside diameters, whichever is applicable, as determined at any one cross-section of the tube.

Tolerances on a given tube may be specified with respect to any two, but not all three of the following: A. Outside dimension B. Inside dimension C. Wall thickness.

When the tube is ordered by O.D. and I.D. the maximum plus and minus deviation of the wall thickness from the mean at any point shall not exceed by more than 50% the values of specified diameter.

The Length Information:

1. Mill Lengths-Certain uniform lengths subject to established tolerances with short lengths included according to established agreement with customer.
2. Random Lengths-Run of the mill lengths without any indicated preferred length, subject to customer approval.
3. Specific Lengths-Indicated uniform lengths, subject to established length tolerances; for example: 12'-0", 9'-7" or 0'-4 1/2" is a specific length. Unless specified otherwise, tolerances are per ASTM B-251.

Weight Per Foot Formula:

To determine weight per linear foot of a seamless tube, when outside diameter (O.D.) is given: 1. Subtract wall thickness from O.D., and then multiply by wall thickness. 2. Using figure from step one, multiply by 11.5736 for brass or 12.1768 for copper.