How much should I reduce torque if the bolt threads are oiled?

The chart states torque values are based on clean, dry threads, and to reduce the value by 10% if threads are oiled prior to assembly.

How can I identify an SAE bolt's grade from its head markings?

The chart notes the number of lines on the bolt head is always 2 less than the grade number — e.g., a Grade 5 bolt has 3 lines.

What is the maximum torque for a 1/2-13 Grade 5 bolt?

75 Ft./Lbs. (10.4 Kgm, 101.7 Nm) per the U.S. Bolts table.

Is there a torque difference between fine and coarse threads?

No — the chart states there is no torque difference for fine or coarse threads.

What torque applies to a 10 x 1.25 mm class 8.8 metric bolt?

20–29 Ft./Lbs. (2.7–4.0 Kgm, 27–39 Nm) per the Metric Bolts table.

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Standard & Metric Bolt Torque Specifications Chart – SAE Grade & Fastener Markings

Standard Torque Specifications & Fastener Markings Chart (U.S. & Metric Bolts)

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General fastener torque chart giving maximum safe torque by SAE grade (1-2, 5, 6-7) and metric class for clean dry threads, in ft-lbs, kg-m and Nm.

AI caption February 2008 · Photo 46 of 46

This document is a general-purpose bolt torque specification chart titled "Standard Torque Specifications and Fastener Markings," commonly included in automotive repair manuals. It provides maximum safe torque values to use when no specific torque is published, covering both U.S. (SAE) and metric fasteners. For U.S. bolts, torque values are listed by bolt size and thread pitch (1/4 in. through 1 in.) across three SAE strength grades (Grade 1 or 2, Grade 5, and Grade 6 or 7), with values given in Ft./Lbs., Kgm, and Nm. Illustrations of bolt head markings are included, with a note that the number of radial lines on the head is always two less than the grade number. For metric bolts, torque ranges are listed by thread size and pitch (6x1.0 mm through 24x1.5 mm) for relative strength classes 4.6/4.8 and 8.8, also in Ft./Lbs., Kgm, and Nm. Key guidelines state there is no torque difference between fine and coarse threads, values assume clean dry threads (reduce 10% if oiled), and aluminum components require considerably less torque. A warning at the bottom notes the chart should be used only as a guide.

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Frequently asked questions

How much should I reduce torque if the bolt threads are oiled?: The chart states torque values are based on clean, dry threads, and to reduce the value by 10% if threads are oiled prior to assembly.
How can I identify an SAE bolt's grade from its head markings?: The chart notes the number of lines on the bolt head is always 2 less than the grade number — e.g., a Grade 5 bolt has 3 lines.
What is the maximum torque for a 1/2-13 Grade 5 bolt?: 75 Ft./Lbs. (10.4 Kgm, 101.7 Nm) per the U.S. Bolts table.
Is there a torque difference between fine and coarse threads?: No — the chart states there is no torque difference for fine or coarse threads.
What torque applies to a 10 x 1.25 mm class 8.8 metric bolt?: 20–29 Ft./Lbs. (2.7–4.0 Kgm, 27–39 Nm) per the Metric Bolts table.