BS 4882 to ASTM A193 Grade B87 Specifications

(b) studbolt threaded each end with nominal diameter portion at centre

studbolt threaded each end with reduced diameter portion at center

(d) studbolt threaded each end with two reduced diameter portions nominal diameter portion at centre

Studbolts

General
The forms of the studbolts shall comply with those shown in figure 4(a), (b), (c) or (d). Dimensions shall be as given in 3.1.2 to 3.1.8 and tables 16 to 19.

Nominal length

The tolerances on nominal length shall be as given in table 17.
NOTE 1. The preferred nominal lengths are given in table 18.
If lengths other than these are requested (see appendix C) the increments of nominal length should be as follows:
(a) 14 in for lengths up to and including 12 in;
(b) ½ in for lengths over 12 in.
NOTE 2. The length of point is excluded from the nominal length (see 1.2.2.1).

Length of thread

For studbolts having plain portions as shown in figures 4(b), (c) and (d), the basic length of thread shall be equal to the nominal diameter plus 0.375 in.
For studbolts in figures 4(b) and 4(c) , the limits on the length of thread shall be plus 2 pitches, minus 0.

Length of reduced diameter portion

The basic length of the reduced diameter portion shall be equal to 0.6 times the nominal diameter (see figure 4(d) and item (d) (5) of appendix C).
The following tolerences shall apply to this dimension:
(a) +0.030,-0 in for lengths up to and including 1.2 in;
(b) +0.060,-0 in for lengths over 1.2 in and up to and including 2.1 in.

Length of thread plus length of reduced diameter portion

The following tolerances shall apply to this dimension:
(a) ±0.030 in for lengths up to and including 2 in;
(b) ±0.060 in for lengths over 2 in and up to and including 6 in.

Ends

The ends of studbolts shall be finished with a point having an included angle of approximately 90° to a depth slightly exceeding the depth of thread. Nominal lengths of points for reference purposes shall be as given in table 19.

Diameter of plain portion

The diameter of the plain portion shall not exceed the maximum values given in table 16.
NOTE. The diameter of the reduced portion should be stated by the purchaser in the order (see appendix C). Under normal conditions a minimum of 0.95 times the minor thread diameter is used, but for studs subject to particularly onerous conditions (such as high temperature service) diameters less than this may be used.

Diameter of plain portion,maximum and minimum sizes of studbolts: Inch series
Nominal diameter	Nominal diameter design		Reduced diameter design ¹⁾
Nominal diameter	max.	min.	max.	min.
in	in	in	in	in
1/2	0.500	0.496	0.373	0.364
5/8	0.625	0.619	0.474	0.464
3/4	0.750	0.744	0.581	0.571
7/8	0.875	0.867	0.685	0.675
1	1.000	0.992	0.786	0.774
1 ^1/8	1.125	1.117	0.905	0.893
1 ^1/4	1.250	1.242	1.022	1.010
1 ^3/8	1.375	1.365	1.142	1.126
1 ^1/2	1.500	1.490	1.260	1.244
1 ^5/8	1.625	1.615	1.381	1.365
1 ^3/4	1.750	1.740	1.498	1.482
1 ^7/8	1.875	1.865	1.620	1.604
2	2.000	1.990	1.732	1.716
2 ^1/4	2.250	2.240	1.968	1.952
2 ^1/2	2.500	2.490	2.210	2.192
2 ^3/4	2.750	2.740	2.440	2.422
3	3.000	2.990	2.685	2.667
3 ^1/2	3.500	3.485	3.160	3.138
3 ^3/4	3.750	3.735	3.397	3.375
4	4.000	3.985	3.635	3.613
¹⁾ Based on tolerance class h 13 of BS 1916.

Screw threads

Screw threads shall be ISO Unified inch coarse pitch series (UNC) for sizes up to and including 1 in diameter, and 8 threads/in (8 UN series) for sizes 1/4 in and above in accordance with BS 1580.
NOTE. The tolerance class should be stated by the purchaser in the order (see appendix C), but for most conditions the following are applicable:
(a) class 2A (see BS 1580) for grades B7, L7, B7A and B16, B16A, B16B;
(b) class 2AG for other materials.

Tolerances on nominal length of studbolts: inch series
Nominal diameter	Length	Tolerances on length
in	in	in
≤ 1	≤ 6	± 0.030
≤ 1	> 6	± 0.045
> 1 ≤ 2	≤ 7	± 0.045
> 1 ≤ 2	> 7	± 0.060
> 2 ≤ 4	All	± 0.075

Preferred nominal lengths of studbolts: inch series (based on flanges as specified in BS 1560: Section 3.1)
Nominal diameter
	Preferred nominal lengths
	2	2 ^1/4	2 ^1/2	2 ^3/4	3	3 ^1/4	3 ^1/2	3 ^3/4	4	4 ^1/4	4 ^1/2	4 ^3/4	5	5 ^1/4	5 ^1/2	5 ^3/4	6	6 ^1/4	6 ^1/2	6 ^3/4	7	7 ^1/4	7 ^1/2	7 ^3/4	8	8 ^1/4	8 ^1/2	8 ^3/4	9	9 ^1/4	9 ^1/2	9 ^3/4	10	10 ^1/4	10 ^1/2	10 ^3/4	11	11 ^1/4	11 ^1/2	11 ^3/4	12	12 ^1/4	12 ^1/2	13 ^1/2	14	14 ^1/2	15	15 ^1/2	16	16 ^1/2	17	17 ^1/2	18	18 ^1/2	19	19 ^1/2	20	20 ^1/2	21	21 ^1/2	22	22 ^1/2	23 ^1/2	24	24 ^1/2	25	25 ^1/2
1/2	x	x	x	x	x	x	x	x	x	x	x
5/8	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x
3/4					x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x		x				x								x
7/8							x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x				x		x	x			x
1											x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x				x								x
1 ^1/8													x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x								x
1 ^1/4															x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x							x
1 ^3/8																										x	x	x	x	x	x	x	x	x	x	x	x						x
1 ^1/2																									x	x	x	x	x	x	x	x	x	x	x		x		x
1 ^5/8																																	x	x	x	x	x	x	x	x		x				x
1 ^3/4																																	x	x	x	x	x	x	x	x	x		x
1 ^7/8																																									x		x	x	x
2																																												x	x	x	x	x
2 ^1/4																																																x	x	x	x
2 ^1/2																																																		x	x	x	x	x	x	x	x
2 ^3/4																																																					x	x	x	x	x	x	x	x
3																																																										x	x	x	x	x
3 ^1/2																																																															x	x	x	x	x
3 ^{3/4 *}
4*
*Preferred nomial length to be completed in a letter revision of this standard Choke of length. (a) minimum length. This minimum length of studs or studbolts has to ensure a full engagement of nut, i.e with the point protruding above the face of the nut (b) maximum length. There is no precise limit on the maximum length of thread although under normal circumstances, unneccessarly long studs and studbolts are avoided due to cost, and preventing corrosion or unintentional damage to the exposed thread making subsequent nut removal more difficult. studs and studbolts may be chosen as the nect nomial length greater than that required for the thickness and tolerances on the bolted components(e.g. flanges ,gaskets, washers.) The availability of stocked length may also be taken into account. Unnecessary shortening of studs and studbolts should be avoided. Where studs and studbolts are shortened the original manufacture's identification and grade marking should be retained

Table 19. Length of point (see 3.2.6) for studbolts: inch series
Nominal diameter	Length
in	in
1/2	0.057
5/8	0.066
3/4	0.071
7/8	0.078
1 and greater	0.087

ASTM A193 Grade B8T Fastener Coatings

PTFE Coated

Black Phosphated

Zinc Plated

Hot Dip Galvanized

Cadium Plated

Ceramic Coated

Zinc Nickel

Zinc Flake Coated