Designated with nominal composition 54Ni-16Mo-15Cr, Hastelloy C-276 flanges of ASME B16.5 can be manufactured from ASTM B462 Gr. N10276 forgings or ASTM B575 Gr. N10276 plates. It shall be solution annealed and not to be used over 675°C[1250°F]. The pressure-temperature ratings for Hastelloy C-276 flanges are listed in below two tables.

1. Pressure-Temperature Ratings for Hastelloy C-276 Flanges: Metric Unit

Temp. °C	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
−29~38	20.0	51.7	68.9	103.4	155.1	258.6	430.9
50	19.5	51.7	68.9	103.4	155.1	258.6	430.9
100	17.7	51.5	68.7	103.0	154.6	257.6	429.4
150	15.8	50.3	66.8	100.3	150.6	250.8	418.2
200	13.8	48.3	64.5	96.7	145.0	241.7	402.8
250	12.1	46.3	61.7	92.7	139.0	231.8	386.2
300	10.2	42.9	57.0	85.7	128.6	214.4	357.1
325	9.3	41.4	55.0	82.6	124.0	206.6	344.3
350	8.4	40.3	53.6	80.4	120.7	201.1	335.3
375	7.4	38.9	51.6	77.6	116.5	194.1	323.2
400	6.5	36.5	48.9	73.3	109.8	183.1	304.9
425	5.5	35.2	46.5	70.0	105.1	175.1	291.6
450	4.6	33.7	45.1	67.7	101.4	169.0	281.8
475	3.7	31.7	42.3	63.4	95.1	158.2	263.9
500	2.8	28.2	37.6	56.5	84.7	140.9	235.0
538	1.4	25.2	33.4	50.0	75.2	125.5	208.9
550	-	25.0	33.3	49.8	74.8	124.9	208.0
575	-	24.0	31.9	47.9	71.8	119.7	199.5
600	-	21.6	28.6	42.9	64.2	107.0	178.5
625	-	18.3	24.3	36.6	54.9	91.2	152.0
650	-	14.1	18.8	28.1	42.2	70.4	117.3
675	-	11.5	15.4	23.0	34.6	57.6	96.0

*Working pressures by Classes, unit: bar.

2. Pressure-Temperature Ratings for Hastelloy C-276 Flanges: US Customary Unit

Temp. °F	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
-20~100	290	750	1000	1500	2250	3750	6250
200	260	750	1000	1500	2250	3750	6250
300	230	730	970	1455	2185	3640	6070
400	200	700	930	1395	2095	3490	5820
500	170	665	885	1330	1995	3325	5540
600	145	605	805	1210	1815	3025	5040
650	125	590	785	1175	1765	2940	4905
700	110	570	755	1135	1705	2840	4730
750	95	530	710	1065	1595	2660	4430
800	80	510	675	1015	1525	2540	4230
850	65	485	650	975	1460	2435	4060
900	50	450	600	900	1350	2245	3745
950	35	385	515	775	1160	1930	3220
1000	20	365	485	725	1090	1820	3030
1050	-	360	480	720	1080	1800	3000
1100	-	325	430	645	965	1610	2685
1150	-	275	365	550	825	1370	2285
1200	-	205	275	410	615	1030	1715
1250	-	165	220	330	495	825	1370

*Working pressures by Classes, unit: psig.