Prevailing Torque Type Hex Nuts

These standards from ANSI, ASME, ISO, SAE, and others address the materials, construction, and requirements for hex nuts for a variety of applications. This list addresses Prevailing Torque Type Hex Nuts.

IFI-101:2002

Torque-Tension Requirements for Prevailing-Torque Type Steel Hex and Hex Flange Nuts

This standard covers torque-tension requirements for two types of plating: 0.0002/0.0004 in. thickness electrodeposited cadmium plated and lubricated Grades B and C prevailing-torque type steel hex nuts in sizes 1/4 to 1 in., inclusive, and Grades F and G prevailing-torque type steel hex flange nuts in sizes 1/4 to 3/4 in., inclusive; and 0.0002/0.0004 in. thickness electrodeposited zinc clear chromate and lubricated Grades B and C prevailing-torque type steel hex nuts in sizes 1/4 to 1 in., inclusive, and Grades F and G prevailing-torque type steel hex flange nuts in sizes 1/4 to 3/4 in., inclusive.

ASME B18.16M-2004 (R2021)

Prevailing-Torque-Type Steel Metric Hex Nuts and Hex Flange Nuts (B18.16M - 2004)

This Standard covers the general, dimensional, mechanical, and performance data for metric prevailing-torque hex nuts and hex flange nuts of property classes 5, 9, and 10 as defined in ASTM A563M. The inclusion of dimensional data in this Standard is not intended to imply that all of the nut sizes in conjunction with the various options described herein are stock items. Consumers should consult with suppliers concerning lists of stock production prevailing-torque hex and hex flange nuts. B18.16M-2004 is a consolidation and update of B18.16.1M-1979, B18.16.2M-1979 and B18.16.3M-1998.

IFI-545:2006

Mechanical and Performance Requirements for Prevailing-Torque Type Steel Metric Hex Nuts and Flange Nuts

This standard covers the mechanical and performance requirements for five classes of prevailing-torque type steel metric hex and hex flange nuts.

IFI-100/107:2002

Prevailing-Torque Type Steel Hex and Hex Flange Nuts Regular and Light Hex Series

This standard establishes the dimensional, mechanical, and performance requirements for three grades of prevailing-torque type steel hex nuts in sizes No. 4 thru 1-1/2 in., and two grades of prevailing-torque type steel hex flange nuts in sizes 1/4 thru 3/4 in.

ISO 7719:2025

Fasteners - Prevailing torque hexagon nuts - Regular nuts (all metal)

This document specifies the characteristics of prevailing torque (all metal) hexagon regular nuts, in steel and stainless steel, with metric coarse pitch thread M5 to M39, and with product grades A and B. NOTE These nuts are designed with an overall height h min = m min (as specified in ISO 898-2 and ISO 4032 for style 1) plus the prevailing torque feature. h max has been established in function of h min ; therefore, the tolerance ( h max – h min ) does not follow the ISO code system for tolerances (IT system). If in certain cases other specifications are requested, property classes and stainless steel grades can be selected from ISO 898-2 or ISO 3506-2.

ISO 7720:2025

Fasteners - Prevailing torque hexagon nuts - High nuts (all metal) with slot(s)

This document specifies the characteristics of prevailing torque (all metal) hexagon high nuts with slot(s), in steel and stainless steel, with metric coarse pitch thread M5 to M39, and with product grades A and B. NOTE These nuts are designed with m min as specified ISO 4032 and with an overall height h greater than in ISO 7042, in order to accommodate the prevailing torque feature with slot(s); this height h contributes to the nut resistance due to the number of engaged threads. h min values have been calculated as a function of h max together with a ratio h max / D that progresses regularly with increasing diameter; therefore, the tolerance ( h max – h min ) does not follow the ISO code system for tolerances (IT system). If in certain cases other specifications are requested, property classes and stainless steel grades can be selected from ISO 898-2 or ISO 3506-2.

ISO 12126:2012

Prevailing torque type all-metal hexagon nuts with flange with metric fine pitch thread, style 2 - Product grades A and B

ISO 12126:2012 specifies the characteristics of prevailing torque type all metal hexagon nuts with flange (style 2), and metric fine pitch thread with nominal thread diameters from 8 mm up to and including 20 mm, in product grade A for diameter sizes less than or equal to 16 mm and product grade B for diameter sizes greater than 16 mm, and with property classes 6, 8 and 10.

ISO 7044:2012

Prevailing torque type all-metal hexagon nuts with flange, style 2 - Product grades A and B

ISO 7044:2012 specifies the characteristics of prevailing torque type all-metal hexagon nuts with flange (style 2) and threads M5 to M20 inclusive, in product grade A for threads up to and including M16 and product grade B for threads above M16, and with property classes 8, 9, 10 and 12.

ISO 10513:2025

Fasteners - Prevailing torque hexagon nuts - High nuts (all metal), with fine pitch thread

This document specifies the characteristics of prevailing torque (all metal) hexagon high nuts, in steel and stainless steel, with metric fine pitch thread 8 mm to 39 mm, and with product grades A and B. NOTE These nuts are designed with an overall height h min = m min (as specified in ISO 898-2 and ISO 8674 for style 2) plus the prevailing torque feature. h max has been established in function of h min ; therefore, the tolerance ( h max – h min ) does not follow the ISO code system for tolerances (IT system). The wrenching height m w,min corresponds to the values specified for style 1. If in certain cases other specifications are requested, property classes and stainless steel grades can be selected from ISO 898-2 or ISO 3506-2.

ISO 7042:2025

Fasteners - Prevailing torque hexagon nuts - High nuts (all metal)

This document specifies the characteristics of prevailing torque (all metal) hexagon high nuts, in steel and stainless steel, with metric coarse pitch thread M5 to M39, and with product grades A and B. NOTE These nuts are designed with an overall heigth h min = m min (as specified in ISO 898-2 and ISO 4033 for style 2) plus the prevailing torque feature. h max has been established in function of h min ; therefore, the tolerance ( h max – h min ) does not follow the ISO code system for tolerances (IT system). The wrenching height m w,min corresponds to the values specified for style 1. If in certain cases other specifications are requested, property classes and stainless steel grades can be selected from ISO 898-2 or ISO 3506-2.

ISO 10512:2025

Fasteners - Prevailing torque hexagon nuts - Regular nuts (with non-metallic insert), with fine pitch thread

This document specifies the characteristics of prevailing torque hexagon regular nuts (with non metallic insert), in steel and stainless steel, with metric fine pitch thread 8 mm to 39 mm, and with product grades A and B. NOTE These nuts are designed with an overall height equal to m min (as specified in ISO 898-2 and ISO 8673 for style 1) plus the prevailing torque feature. The height of the prevailing torque feature ( h max – m min ) for the non-metallic insert is identical for regular, high and thin nuts for a given diameter. If in certain cases other specifications are requested, property classes and stainless steel grades can be selected from ISO 898-2 or ISO 3506-2.

ISO 7040:2025

Fasteners - Prevailing torque hexagon nuts - Regular nuts (with non-metallic insert)

This document specifies the characteristics of prevailing torque hexagon regular nuts (with non metallic insert), in steel and stainless steel, with metric coarse pitch thread M3 to M39, and with product grades A and B. NOTE These nuts are designed with an overall height equal to m min (as specified in ISO 898-2 and ISO 4032 for style 1) plus the prevailing torque feature. The height of the prevailing torque feature ( h max – m min ) for the non-metallic insert is identical for regular, high and thin nuts for a given diameter. Nuts with sizes D M5 and design principles in accordance with style 1 are specified in Annex A. If in certain cases other specifications are requested, property classes and stainless steel grades can be selected from ISO 898-2 or ISO 3506-2.

ISO 7041:2025

Fasteners - Prevailing torque hexagon nuts - High nuts (with non-metallic insert)

This document specifies the characteristics of prevailing torque hexagon high nuts (with non metallic insert), in steel and stainless steel, with metric coarse pitch thread M5 to M39, and with product grades A and B. NOTE These nuts are designed with an overall height equal to m min (as specified in ISO 898-2 and ISO 4033 for style 2) plus the prevailing torque feature. The height of the prevailing torque feature ( h max – m min ) for the non-metallic insert is identical for regular, high and thin nuts for a given diameter. If in certain cases other specifications are requested, property classes and stainless steel grades can be selected from ISO 898-2 or ISO 3506-2.

ISO 7043:2012

Prevailing torque type hexagon nuts with flange (with non-metallic insert), style 2 - Product grades A and B

ISO 7043:2012 specifies the characteristics of prevailing torque type hexagon nuts with flange (with non-metallic insert), of style 2, with threads from M5 to M20 inclusive, in product grade A for threads up to and including M16 and product grade B for threads above M16, and with property classes 8, 9 and 10.

ISO 12125:2012

Prevailing torque type hexagon nuts with flange (with non-metallic insert) with metric fine pitch thread, style 2 - Product grades A and B

ISO 12125:2012 specifies the characteristics of prevailing torque type all metal hexagon nuts with flange (with non-metallic insert) of style 2, with metric fine pitch thread with nominal thread diameters from 8 mm up to and including 20 mm, in product grade A for diameter sizes less than or equal to 16 mm and product grade B for diameter sizes greater than 16 mm, and with property classes 6, 8 and 10.

ISO 10511:2025

Fasteners - Prevailing torque hexagon nuts - Thin nuts (with non-metallic insert)

This document specifies the characteristics of prevailing torque hexagon thin nuts (with non metallic insert), in steel and stainless steel, with metric coarse pitch thread M3 to M39, and with product grades A and B. NOTE These nuts are designed with an overall height equal to m min (as specified in ISO 898-2 and ISO 4035 for style 0) plus the prevailing torque feature. The height of the prevailing torque feature ( h max – m min ) for the non-metallic insert is identical for regular, high and thin nuts for a given diameter. Nuts with sizes D M5 and design principles in accordance with style 0 are specified in Annex A. WARNING — Thin nuts (style 0) have a reduced loadability compared to regular or high nuts, they are not designed to provide resistance to thread stripping (see ISO 898-2). If in certain cases other specifications are requested, stainless steel grades and property classes can be selected from ISO 3506-2.