Bolting for ANSI B16.5 & BS3293 Flanges – Dimensions

To suit R.F. Flange sizes DN 15 to 600 to ANSI B16.5 and DN 750 & 900 to BS3293

Diameter of Bolts is shown in inches. For nominal diameters 1 inch and smaller, threads are U.N.C.; nominal diameters 11/8 inch and larger threads are 8 U.N. (8 T.P.I.).

Length of Bolts (L) is shown in millimetres rounded to the nearest 5mm. Stud Bolt lengths (L*) do not include the height of points. Machine Bolt lengths (L) include the height of point.

The length shown includes the height of the Raised Face in all cases.

NOMINAL SIZES SHOWN ARE
V DN: SI METRIC TERM
I NPS: ANSI TERM

NOMINAL FLANGE SIZE PN20 (CLASS 150) PN50 (CLASS 300) PN100 (CLASS 600) PN150 (CLASS 900) PN250 (CLASS 1500) PN420 (CLASS 2500) NOMINAL FLANGE SIZE
No. Bolts Dia. Bolts ins. L No. Bolts Dia. Bolts ins. L No. Bolts Dia. Bolts ins. L No. Bolts Dia. Bolts ins. L No. Bolts Dia. Bolts ins. L No. Bolts Dia. Bolts ins. L
Stud
Bolts mm		 Mach.
Bolts mm		 Stud
Bolts mm		 Mach.
Bolts mm		 Stud
Bolts mm		 Stud
Bolts mm		 Stud
Bolts mm		 Stud
Bolts mm
V
DN		 I
NPS		 V
DN		 I
NPS
15 ½ 4 ½ 60 45 4 ½ 65 55 4 ½ 80 USE PN250 DIMENSIONS IN THESE SIZES 4 ¾ 105 4 ¾ 125 15 ½
¾ 1
20 ¾ 4 ½ 65 50 4 5/8 75 60 4 5/8 90 4 ¾ 115 4 ¾ 125 20
25 1 4 ½ 65 55 4 5/8 80 65 4 5/8 90 4 7/8 125 4 7/8 140 25
32 1¼ 4 ½ 70 55 4 5/8 80 65 4 5/8 100 4 7/8 125 4 1 150 32 1¼
40 1½ 4 ½ 70 60 4 ¾ 90 75 4 3/4 105 4 1 140 4 1-1/8 170 40 1½
50 2 4 5/8 80 65 8 5/8 90 75 8 5/8 105 8 7/8 145 8 1 175 50 2
65 2½ 4 5/8 90 75 8 ¾ 100 85 8 ¾ 120 8 1 160 8 1-1/8 195 65 2½
80 3 4 5/8 90 75 8 ¾ 110 90 8 ¾ 125 8 7/8 145 8 1-1/8 180 8 1-¼ 220 80 3
90 3½ 8 5/8 90 75 8 ¾ 110 95 8 7/8 140 – – – – – – – – – 90 3½
100 4 8 5/8 90 75 8 ¾ 110 95 8 7/8 145 8 1-1/8 170 8 1-¼ 195 8 1-½ 255 100 4
125 5 8 ¾ 90 80 8 ¾ 120 100 8 1 165 8 1-¼ 190 8 1-½ 250 8 1-¾ 300 125 5
150 6 8 ¾ 100 85 12 ¾ 125 105 12 1 170 12 1-1/8 195 12 1-3/8 260 8 2 345 150 6
200 8 8 ¾ 110 90 12 7/8 140 110 12 1-1/8 195 12 1-3/8 220 12 1-5/8 290 12 2 380 200 8
250 10 12 7/8 115 95 16 1 155 130 16 1-¼ 215 16 1-3/8 235 12 1-7/8 335 12 2-½ 485 250 10
300 12 12 7/8 120 100 16 1-1/8 170 145 20 1-¼ 220 20 1-3/8 255 16 2 375 12 2-¾ 540 300 12
350 14 12 1 130 110 20 1-1/8 175 150 20 1-3/8 235 20 1-½ 275 16 2-¼ 405       350 14
400 16 16 1 135 115 20 1-¼ 190 160 20 1-½ 255 20 1-5/8 285 16 2-½ 445 400 16
450 18 16 1-1/8 150 125 24 1-¼ 195 170 20 1-5/8 275 20 1-7/8 325 16 2-¾ 495 450 18
500 20 20 1-1/8 160 135 24 1-¼ 205 180 24 1-5/8 290 20 2 345 16 3 540 500 20
600 24 20 1-¼ 175 145 24 1-½ 230 195 24 1-7/8 330 20 2-½ 435 16 3-½ 615 600 24
750 30 28 1-¼ 190 160 28 1-¾ 290 250 28 2 355 PN150, 250 & 420 – Not listed in BS 3293 750 30
900 36 32 1–½ 215 180 32 2 325 280 28 2-½ 400 900 36

Raised Face height of 1.6mm for PN20 & 50 and 6.4mm for PN100, 150, 250 & 420 is included in dimension L (Bolt Length).

Material Specifications

ASTM A193 Grade B7
Standard specification for alloy steel and stainless steel bolting materials for high temperature service.
ASTM A194 Grade 2H
Standard specification for carbon and alloy steel nuts for bolts for high pressure and high temperature service.
ASTM A320
Standard specification for alloy steel bolting materials for low temperature service.
Grade L7 covers alloy steel stud bolts.
Grade L4 covers alloy steel nuts to suit Grade L7 stud bolts.