Fully Threaded Stud Bolts

Standard Specifications

We will introduce the standard specifications of the Fully Threaded Stud Bolts for you in these three aspects.

（1）Dimensional Standards

Metric: DIN 975, DIN 976, ISO 898-1

Imperial (Unified): ANSI/ASME B18.31.1, UNC / UNF thread series

Thread tolerance:Metric: Class 6g

Imperial: Class 2A

（2）Material & Strength Grades

Carbon Steel

Grade 4.8 / 5.6 – light duty, general assembly

Grade 8.8 – most common for machinery and structural work

Grade 10.9 / 12.9 – high strength, heavy loads

Alloy Steel (High Temp / Pressure)

ASTM A193 B7 – standard for high‑temperature, high‑pressure flanges and piping

ASTM A193 B16 – for even higher temperature service

Stainless Steel

304 (A2) – good general corrosion resistance

316 (A4) – better for marine, chemical, and coastal environments

Typically meet ISO 3506‑1 property classes A2‑70, A4‑70, or A4‑80

（3）Surface Finishes (by standard)

Zinc plating – basic protection, common for indoor use

Hot‑dip galvanizing – thicker coating for outdoor and corrosive environments

Black oxide – light protection, non‑reflective finish

Stainless steel – no coating required; passivated per ASTM A967

Structural Features

The structure of the Fully Threaded Stud Bolts is the most distinctive feature. If you are interested, please contact us.

（1）Full-thread continuous structure

Integral thread: The entire length from one end to the other is threaded, without any smooth sections.

Any cutting: You can cut as long as you want, and after cutting, you can also tighten the nuts.

Continuous force application: The threads are evenly distributed and the force is applied evenly.

（2）Thread processing method (rolling)

Rolling process: The thread is not cut but is formed by pressing with a rolling plate or a rolling machine.

Continuous metal fillet: Rolling does not cut the material fibers, and the root of the thread is more compact. The fatigue strength and tensile strength are higher than those of threaded parts produced by turning.

Smooth surface: There are no burrs or scratches left from cutting. The nut can be screwed on smoothly and does not get stuck easily.

（3）No head design

Symmetrical at both ends: No hexagonal or square heads, both ends have threads.

Installation is flexible: It can be inserted from either end, making it suitable for situations where space is limited and operation can only be performed on one side.

Installation Notes

Whether you have purchased the Fully Threaded Stud Bolts or not, please be sure to read the following content as it will be of great help to you.

（1）Thread matching: Try tightening the corresponding nut to confirm that the thread specifications (metric/English, coarse thread/finer thread) are consistent.

（2）End treatment: If the studs are cut on-site, check whether the cut surface is smooth, and look for any burrs or deformities. The cut surface should be smoothed out with a file or a chamfering tool.

（3）Cleaning: If there is any oil, rust or debris on the surfaces of the studs and nuts, clean them thoroughly first.

（4）Symmetrical tightening from both ends: If it is a double nut locking, try to tighten them alternately.

（5）Using a torque wrench: It will be much more convenient to use the tool.

（6）Avoid thread seizing: It is recommended to apply a small amount of anti-seizing agent to the threads.

（7）Install anti-loosening devices: Use spring washers, double nuts (tightening), nylon anti-loosening nuts or apply thread sealant.

（8）Spring pins / slotted nuts: For critical parts (such as suspension, rotating components), they are used in conjunction with slotted nuts and spring pins.

（9）Regular re-tightening: Check the torque once a few days after installation or at the beginning of equipment operation to prevent initial loosening.