ASTM A394 Grade 1 Bolting Specification

Structural & Transmission Tower Bolts

ASTM A394 Grade 1 Hex Bolts, Square Bolts, Tower Bolts & Nuts

ASTM A394 Grade 1 Tower Bolts & Nuts both hexagon and square-head zinc-coated steel bolts and atmospheric corrosion-resistant bolts, in nominal thread diameters of 1/2 , 5/8 , 3/4 , 7/8 and 1 inch are used in the construction of transmission towers, substations, and similar steel structures. Type 0 and Type 1 bolts shall be hot-dip zinc-coated accordance with the requirements of Specification F2329, except that the minimum average weight (thickness) of zinc coating shall be 1.65 oz/ft2 (0.0028 in.) and the minimum weight of zinc coating on any one item shall be 1.50 oz/ft 2 (0.0025 in.).When non-zinc-coated atmospheric corrosion- resistant steel is required, Type 3 bolts shall be specified by the purchaser. ASTM A394 Type 0 Ladder bolts, step bolts, and equipment support bolts are also Manufactured at TorqBolt.

Related Specifications of ASTM A394 Grade 1 Bolting

A563 F436


Bolt Type Nut Grade Finish
ASTM A394 Grade 1 DH hot-dip zinc-coated

ASTM A394 Grade 1 Chemical requirements

Element Analysis Bolts Types
Type 1 Bolts A
C Heat Analysis 0.28/0.55
Product Analysis . . .
Mn Heat Analysis 0.60 min
Product Analysis . . .
P Heat Analysis 0.048 max
Product Analysis  
B Heat Analysis
Product Analysis
S Heat Analysis 0.058 max
Product Analysis
Si Heat Analysis
Product Analysis
Cu Heat Analysis
Product Analysis
Ni Heat Analysis
Product Analysis
Cr Heat Analysis
Product Analysis
V Heat Analysis
Product Analysis
Mo Heat Analysis
Product Analysis
Ti Heat Analysis
Product Analysis
  • (A) A, B, C, D, E, and F are classes of material used for Type 3 bolts. Selection of a class shall be at the option of the bolt manufacturer.
  • (B) These elements are not specified or required.

ASTM A394 Grade 1 Mechanical Properties

ASTM A394 Grade 1 Hardness Requrments

 Types Min Max
ASTM A394 Types 1-Rockwell C 25 34

ASTM A394 Grade 1 Tensile Strength

Nominal Size, in. Minimum Tensile Load, lbf
Type 0B Types 1 and 3C
1/2 10 500 17 050
5/8 16 700 27 100
3/4 24 700 40 100
7/8 34 200 55 450
1 44 850 72 700
  • (A) Based on 74 000 psi unit tensile strength.
  • (B) Based on 120 000 psi unit tensile strength.

ASTM A394 Grade 1 Shear Strength

Nominal Size, in. Minimum Load, lbf
Types 1
Single Shear Strength Through Threads, lbf C
1 / 2 9 350 14 600
5 / 8 15 050 22 850
3 / 4 22 450 32 850
7 / 8 31 150 44 750
1 41 000 58 450
  • (A) Based on 55 200 psi unit shear strength across the area at root of threads.
  • (B) Based on 45 880 psi unit shear strength across the nominal area.
  • (C) Based on 74 400 psi unit shear strength across the area at root of threads.
  • (D) Based on 74 400 psi unit shear strength across the nominal area.

ASTM A394 Grade 1 Dimensions Length of Full Body for Bolts A

Length of Bolt, L, in. Bolt Diameter, in.
1/2 5/8 3/4 7/8 1
1 3/32 1/16 ... ... ...
11/4 5/32 1/16 1/16 ... ...
11/2 13/32 1/4 1/8 3/16 ...
13/4 21/32 1/2 3/8 1/4 3/16
2 and longer in 1/4-in. increments L minus 13/32 L minus 11/4 L minus 13/8 L minus 11/2 L minus 15/8
  • (A) Full body length is the distance from the underside of the head to the first scratch of thread for bolts with machine-cut threads or to top of the extrusion angle for bolts with rolled threads with a tolerance of ±1/32 in. for sizes 1/2 in. through 3/4 in., inclusive, and ±1/16 in. for size 7/8 in. and 1 in.

ASTM A394 Grade 1 Coating Tolerances

Nominal Bolt Diameter, in. Oversize Limit, in.A
Hot-Dip Zinc
1/2 0.018
5/8 , 3/4 0.020
7/8 0.022
1 0.024
  • (A) Hot-dip zinc-coated nuts are tapped oversize after coating.

ASTM A394 Grade 1 Bolting Surface Treatment Specifications

A153/A153M Specification for Hot Dip Galvanising (Zinc Coating) on Iron and Steel Hardware
B633 Specification for Electrodeposited Coatings of Zinc on Iron and Steel
B695 Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel
B696 Specification for Coatings of Cadmium Mechanically Deposited
B766 Specification for Electrodeposited Coatings of Cadmium
F1941/F1941M Specification for Electrodeposited Coatings on Mechanical Fasteners, Inch and Metric
F2329/F2329M Specification for Zinc Coating, Hot-Dip, Requirements for Application to Carbon and Alloy Steel Bolts, Screws, Washers, Nuts, and Special Threaded Fasteners

ASTM A394 Grade 1 Bolting Components Marking

Product Shall be Marked with our manufacturing trade mark "TorqBolt" or "TB" along with the designated Grade.
Grade and manufacturer’s identification symbols shall be applied to one end of studs and to the heads of bolts and screws of all sizes. (If the available area is inadequate, the grade symbol may be marked on one end and the manufacturer’s identification symbol marked on the other end.) For bolts and screws smaller than 1⁄4 in. [6 mm] in diameter and studs smaller than 3⁄8 in. [10 mm] in diameter and for 1⁄4 in. [6 mm] in diameter studs requiring more than a total of three symbols, the marking shall be a matter of agreement between the purchaser and the manufacturer.

Grade Marking
ASTM A394 Type 1  TB 1

ASME Dimensional Standards

B18.2.1 Imperial Square and Hex Bolts and Screws

ASTM A394 Grade 1 Bolting Certifications

  • EN 10204 3.1
  • EN 10204 3.2
  • PED 2014/68/EC
  • MERKBLATT AD 2000 W2/W7/W10
  • API 20 E BSL 1/ BSL 2
  • NACE MR 0175
  • NACE MR 0103

ASTM A394 Grade 1 Testing Standards

F606/F606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets F788/F788M Specification for Surface Discontinuities of Bolts, Screws, and Studs, Inch and Metric Series F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection G101 Guide for Estimating the Atmospheric Corrosion Resistance of Low-Alloy Steels

ASME Threading Specifications

ASME B1.1 Unified Inch Screw Threads (UN and UNR Thread Form)
ASME B1.3 Screw Thread Gaging System for Dimensional Acceptability - Inch Screw Threads (IN, UNR, and UNJ)
ASME B1.13M Metric Screw Threads- M Profile
ASME B1.21M Metric Screw Threads - MJ Profile
ASME B1.2 Gauges & gauging for Unified Screw Threads(Imperial)