Coupling Nuts

Stainless Steel Hexagon Coupling Nut Manufacturer in India

Ramesh Steel Corporation, was incepted in 1983 by Mr. Ramesh D Jain, a renowned name in Steel Industry, Ramesh Steel corporation is known as a specialist of manufacturing steel Fasteners ,Duplex Steel Fasteners, Stainless Steel Fasteners, Coupling Nuts, Bolts ,Nuts ,Screws & Washer since more than 3 decades ,Mr. Ramesh D. Jain is having more than 35 years of experience in manufacturing of customized Fasteners depends upon the requirements of our clients based in Saudi Arabia, Kuwait, Turkey, United Arab Emirates, Oman, Egypt, Indonesia, Malaysia, Singapore, Thailand, Sri Lanka, Russia, West Africa & Latin America

Coupling Nuts

Ramesh Steel Corporation we stand behind our products, a team of our experienced engineers, we dedicate for complex & strict defined requirements, we have manufactured fasteners based on complex drawings where many companies have refused to manufacture the same to our customers because of their complexity & requirements of special grades, Ramesh Steel Corporation is Centrally located in Mumbai, India, Ramesh Steel Corporation has played a vital role in the growth of Duplex Steel Fasteners, Stainless Steel Fasteners, Coupling Nuts, Bolts & Nuts Screws & Washer, we are manufacturing Fasteners in different metals & grades like Nickel 200/201, Monel 400/K500, Inconel 600, Inconel 625, Inconel 800, Inconel 825, Hastelloy C22/ C276, Alloy 20, Titanium, Duplex & Super Duplex in form of Coupling Nuts bolts, Nuts, Screws, Washers Etc.

Coupling Nuts

Coupling Nut Applications

Coupling nuts are used to make up long tie rod assemblies from shorter lengths of rod and to facilitate assembly of two fasteners or fittings which each have external threads.

Relevant Standards

Coupling nut dimensions are described by the Industrial Fasteners Institute in standard IFI-128. Chemical and mechanical properties are controlled in conformance with ASTM and SAE nut specifications (ASTM A563, ASTM A194 and SAE J995).


Standard coupling nuts are produced from ASTM A108 grade 12L14 hexagon or round bars with 50 Ksi minimum yield strength. Other available materials include 1045, 4140, structural grades and stainless steels.


Standard finish is plain with either a cold drawn or hot rolled mill finish, depending on the type of bar stock used. Hot dip galvanizing is available as well as zinc electroplating.


Standard threads are UNC 2B, RH, with other thread series and profiles available by special order. Hot dip galvanized coupling nuts are normally tapped oversize after galvanizing to accommodate the zinc coating on the rod threads. Coupling nuts up to 1-1/2" thread size are tapped all the way through from one end, allowing them to be completely threaded on to one of the members which are to be coupled, a feature that is required for certain assembly situations. Coupling nuts larger than 1-1/2" thread size cannot be tapped all the way through without special extended length taps and are therefore furnished with RH/RH threads (tapped to a depth of L/2 from each end) unless specifically ordered as 'threaded all the way through'.

Coupling nuts can also be threaded with two different thread sizes or profiles. These parts are normally identified as 'reducing coupling nuts'.


Refer to the coupling nut table for dimensions. Some of the sizes listed in this table have an 'Across Flats Size' slightly larger than that called for by IF-128 due to commercial availability of hexagon bar stock. Because of limited availability of hex stock larger than 3-1/2", coupling nuts with thread sizes 2-1/2" and larger are usually made from round bar. These larger parts can be provided with milled wrench flats or a milled hex.

Notes Regarding Strength

Standard coupling nuts meet the chemical and mechanical requirements of ASTM A563 grade A. When high strength rods are specified, coupling nuts produced to meet ASTM A563 grade DH and A194 grade 2H or grade 7 can be provided. These parts will meet all of the chemical and mechanical properties called for in those specifications.

In order to meet the above strength requirements, the rods must be threaded into the coupling nut for a distance equal to or greater than the nominal thread diameter.

The IFI-128 specification describes an optional cross hole located at L/2, (also known as a 'sight hole') which allows visual verification that the threads are fully engaged.

Coupling Nuts Dimensions

Across Flats
Across Points
1/2 3/4 7/8 1-1/2 0.12
5/8 1 1-1/8 1-7/8 0.30
3/4 1-1/8 1-5/16 2-1/4 0.42
7/8 1-5/16 1-7/16 2-5/8 0.56
1 1-1/2 1-3/4 3 0.99
1-1/8 1-5/8 1-7/8 3-3/8 1.23
1-1/4 1-7/8 2-3/16 3-3/4 1.93
1-3/8 2 2-5/16 4-1/8 2.31
1-1/2 2-1/4 2-5/8 4-1/2 3.33
1-5/8 2-3/4 3-3/16 4-7/8 6.17
1-3/4 2-3/4 3-3/16 5-1/4 6.16
1-7/8 3 3-7/16 5-5/8 7.61
2 3-1/4 3-7/16 6 9.69
2-1/4 3-1/2 4-1/16 6-3/4 12.7
2-1/2 3-7/8 4-1/2 7-1/2 17.2
2-3/4 4-1/4 4-15/16 8-1/4 22.7
3 4-5/8 5-5/16 9 29.2
3-1/4 5 5-3/4 9-3/4 36.8
3-1/2 5-3/8 6-3/16 10-1/2 45.8
3-3/4 5-3/4 6-5/8 11-1/4 56.0
4 6-1/8 7-1/16 12 68.0
4-1/2 6-7/8 7-15/16 13-1/2 96.0
5 7-5/8 8-13/16 15 130.0

Item Coupling Nut
Type Standard
Material Steel
Finish Zinc Chromate Plated
Grade 2
Thread Size 3/8-16
Thread Style Fully Threaded
Thread Type UNC
Thread Direction Right Hand
Width 5/8"
Length 1-3/4"
Min. Tensile Strength (PSI) 50,000
Min. Yield (PSI) 40,000
Application Straight Line Pull Max. 2600 Lbs.
Package Quantity 10

Coupling Nuts Price

Rod Coupling Nut, Grd 2, 3/8-16, Pk10
FOB Price: $13.09 to $19.09
Package Qty. 10