ASTM F3125-26 and the 2025 RCSC Specification: Grade 144 bolts, no calibrated wrench

Two documents that govern high-strength structural bolting in North America have moved on. ASTM lists F3125/F3125M-26 as the active edition of the structural bolt specification. Separately, the Research Council on Structural Connections (RCSC) published a new Specification for Structural Joints on 5 June 2025, superseding the 2020 edition. The RCSC document is free to download, so we read its changes directly. The ASTM text is paid, so this note sticks to what ASTM states on its product pages.

Why it matters for design engineers

Grade 144 is now a full F3125 grade. The -26 scope says one additional grade, 144 ksi, is added in two types and two styles for inch sizes only, furnished from 1/2 to 1-1/4 in. The grade appears in the -25 edition too, so it is not new in 2026. It is new to you if your specification still quotes -19. RCSC 2025 Table 2.1 adds F3125 Grade 144 heavy hex and twist-off bolts. The commentary keeps the rule that Group 144 bolts are installed to the same minimum pretension as Group 150.

Minimum pretension did not change. We compared Table 5.2 of the 2020 and 2025 RCSC editions row by row, and the values are identical. At 3/4 in, for example, they are 28 kip (Group 120) and 35 kip (Groups 144 and 150). RCSC states these are 70 % of the minimum tensile strength times the tensile stress area, rounded to the kip.

The calibrated wrench method is gone. The 2025 preface records the calibrated wrench method as withdrawn from Sections 7.2, 8.2 and 9.2 (verification, installation and inspection). The glossary now names four pretensioning methods: turn-of-nut, twist-off tension control bolt, direct tension indicator and the combined method. A torque value is still used in the combined method, where a calibrated installation wrench applies an initial torque before a specified rotation. Table 7.4, the minimum torques for that method, was revised.

What to check:

If your document says	Check
ASTM F3125-19 or earlier	Whether the project allows the current edition, and whether Grade 144 should be permitted or excluded
Calibrated wrench installation	Whether the governing RCSC edition is 2020 or 2025; under 2025 choose another method
Galvanised or reused bolts	RCSC 2025 Sections 2.8.1 and 2.11.1, which now address Group 144
F1136, F2833 or F3019 coatings	RCSC 2025 lists these as withdrawn in 2025 and points to ASTM F3393

Our tools

The pretension column of our ASTM F3125 chart matches Table 5.2 of both editions. The chart previously labelled it “Table 8.1”. In the 2020 and 2025 editions, Table 8.1 is the turn-of-nut rotation table and the pretension table is Table 5.2. The chart now cites RCSC 2025 Table 5.2. Its torque columns remain planning estimates. RCSC has never accepted a torque from a table as an installation method, and the 2025 edition removes the calibrated wrench altogether.

The chart and the bolt torque calculator cover Grades A325 and A490 only. Grade 144 is not yet a selectable grade.