Reference Source

A268 · S43940

For A268 · S43940, astm specification is A268; class or grade is S43940; esab preheat group is C; esab-recommended mcaw (metal-cored) filler is AR MC18CrCb; suggested preheat, low hydrogen (h8 and less), by thickness is T < .75: 200, .75 < T < 1.5: 300, 1.5 < T < 2.5: 300, T > 2.5: 350, recorded from its source on 2026-09-16.

ASTM specification
A268 verified
Class or grade
S43940 verified
ESAB preheat group
C verified
ESAB-recommended MCAW (metal-cored) filler
AR MC18CrCb verified
Suggested preheat, low hydrogen (H8 and less), by thickness
T < .75: 200, .75 < T < 1.5: 300, 1.5 < T < 2.5: 300, T > 2.5: 350 our reading
Suggested preheat, hydrogen above H8, by thickness
T < .75: NR, .75 < T < 1.5: NR, 1.5 < T < 2.5: NR, T > 2.5: NR our reading
Sourceassets.esab.com
Verified
Review by
DatasetESAB recommended filler metals and suggested preheat group, by ASTM steel grade

Values marked our reading are our classification of what the source says — the source does not print them in those words. The quote below is the evidence for each one; judge it yourself.

What the source says

A268 TP405 C OK 68.17 Autrod/Tigrod 410NiMo TP409 C AR 309/309H/308/308H, OK 61.25 Autrod/Tigrod 409Nb TP429 C AR 309L, OK 67.13 Autrod/Tigrod 309L/309Si/310 TP430Ti C Autrod/Tigrod 430Ti/430LNb TP439 C TP444 C AR 316L Autrod/Tigrod 316L/316LSi S41500 C OK 68.17 Autrod/Tigrod 410NiMo S43940 C

assets.esab.com, retrieved 2026-09-16

Where each value comes from

This source states these in separate places, so each value is shown with the passage that states it.

ESAB-recommended MCAW (metal-cored) filler

AR MC18CrCb

Suggested preheat, low hydrogen (H8 and less), by thickness and Suggested preheat, hydrogen above H8, by thickness

Preheat A B C D Low Hydrogen H8 and less T < .75 70 70 200 300 .75 < T < 1.5 70 125 300 400 1.5 < T < 2.5 150 200 300 400 T > 2.5 225 300 350 500 Hydrogen > H8 T < .75 175 175 NR NR .75 < T < 1.5 225 225 NR NR 1.5 < T < 2.5 275 275 NR NR T > 2.5 300 300 NR NR

— all from assets.esab.com, retrieved 2026-09-16

Source

Last verified against source: . Due for re-check by . This page as Markdown · OKF bundle · full dataset as JSON.