Pipe Fitter’s Mate

Technical Resource

Pipe Fitter’s Mate

Pick the application, then select size, get the dimension, fittings included.

Note: always double check current batch of fittings for mill tolerance variation.

Or click any value in the chart below.
Nominal wall thickness
Outside diameter
Approx. mass

Carbon steel wall thickness chart

ASME B36.10, all values in mm. Selection highlighted. Scroll sideways for the heavier schedules.

Or click any value in the chart below.
Nominal wall thickness
Outside diameter
Inside diameter
Approx. mass

Stainless wall thickness chart

ASME B36.19, all values in mm. Wall thickness with inside diameter underneath in lighter type.

Elbows, return bends and caps

ASME B16.9 long radius and caps, ASME B16.28 short radius. All values in mm. Click a row to load it above.

Tees and reducers

ASME B16.9. Equal ends are the straight tee. All values in mm. Click a row to load it above.

Lap joint stub ends

ASME B16.9, long and short pattern. All values in mm. Click a row to load it above.

What the dimensions mean

Centre lines dashed, dimensions in copper. Faces are the weld prep ends, so every dimension runs to the end of the fitting. On a return bend, O is the centre to centre spacing of the two legs.

A 90 deg long radius elbow, centre to face. ASME B16.9.
B 45 deg long radius elbow, centre to face. ASME B16.9.
K 180 deg long radius return bend. O is centre to centre of the legs, K is back to face. ASME B16.9.
D 90 deg short radius elbow, centre to face. ASME B16.28.
V 180 deg short radius return bend. O is centre to centre of the legs, V is back to face. ASME B16.28.
E Cap, overall length. ASME B16.9.
C Tee, centre to end of run. Same both sides on a straight tee.
M Reducing tee, centre to end of the branch outlet.
H Concentric or eccentric reducer, overall length.
F Lap joint stub end. F is overall length, long or short pattern. G is the lap outside diameter, R the fillet radius. ASME B16.9.

Elbows, return bends and caps

ASME B16.9 long radius and caps, ASME B16.28 short radius. All values in mm.

Tees and reducers

ASME B16.9. Equal ends are the straight tee. All values in mm.

Source. Nominal dimensions to ASME B36.10M for carbon steel pipe, ASME B36.19M for stainless pipe, ASME B16.9 for buttwelding fittings, and ASME B16.28 for short radius elbows and return bends. Carbon steel mass is (OD − t) × t × 0.02466 kg/m. Stainless mass uses 0.02491 kg/m, based on 7.93 kg/dm3 for austenitic grades. A dash means the size is not made in that schedule or the dimension does not apply.

These are nominal values. Mill tolerance, commonly −12.5% on wall thickness, and any corrosion allowance both come off before you check a wall against design pressure to AS 4041 or ASME B31.3. STD, XS and XXS overlap the numbered schedules in the smaller sizes, which is why the tool tells you when the wall you have selected is identical to another schedule. Order to the schedule, not to the thickness.

Stainless S schedules are not the carbon steel schedules. Sch 40S and Sch 40 agree up to DN 250, then part company. Sch 80S is capped at 12.70 mm from DN 250 up, where Sch 80 keeps climbing. Two flagged cells: at DN 250 and DN 300 the source marks Sch 80S with an asterisk for this reason.

Inside diameter is calculated, not transcribed. The stainless chart works out inside diameter as OD minus twice the wall, so it can sit 0.01 mm off a printed figure through rounding. One published cell is properly out: DN 300 Sch 40S prints as 304.08 mm where the arithmetic gives 304.81 mm, so the chart shows the calculated value.

Need a hand with the procedures, or the fitting itself? Pipe work is what Graham grew up doing. Spools, headers, pressure pipe. Whether it’s a WPS that needs writing, a fitting process running slower than it should, or a crew that needs training to fit and tack properly, that’s his specialty. Talk to Graham.