DOING WHATEVER IT TAKES

Process

Built for Strength, Reliability, and Performance

At U.S. Bolt Manufacturing, our commitment to quality begins with a rigorous, high-integrity manufacturing process designed to produce bolting that meet the most demanding industry standards. From raw material selection to precision forging, heat treatment, and meticulous quality control, every step is engineered to ensure superior strength, reliability, and performance.

Raw Material

Premium quality bolting can't be produced from raw material of inferior quality. Our raw material inventory is produced to exacting U.S. Bolt material specifications, which are written to control the melt and rolling practices, as well as dictating the chemistry and material cleanliness. We perform on-site audits of our producing steel mills and closely monitor their output. These quality audits are performed by our professional metallurgical staff, assuring fully understood customer requirements and mill practices.

High Strength / Low Alloy Steel: 4140 4340

Iron Based Super-alloy: A286

API 20F: ASTM A453, Gr. 660 API 6ACRA

(Alloy 716, Alloy 718, Alloy 725, Alloy 925, Alloy 935, and Alloy 945)

We are not limited to the options listed.

Forging

Our in-house forging is accomplished through the use of 7 vertical forging presses. We have the ability to forge alloy steel bolting from ¼” diameter, through 5 ¾” diameter. Precision control of forging billet heating is assured through our manufacturing processes, virtually eliminating the potential for heat damage of the forgings. We can hot upset forge bolt heads and hex nuts in almost any high strength, low alloy steel or heat resistant super alloy. Bolt / Screw Head and Nut configurations include: Hex, 12 Point Flange, Hex Flange, Hex Socket and specials. Forging processes are planned and implemented by our Manufacturing Engineering staff.

Heat Treatment

We employ state-of-the-art heat treating equipment to insure the most precise, homogeneous metallurgical structure possible. Our gas fired, batch-type furnaces feature radiant tube heating and closely controlled zones, eliminating the potential for “hot spots” and flame impingement. Our high-temperature furnaces are equipped with internal, integrated quench tanks, providing the most rapid oil/polymer quenching possible. Heat treated product uniformity is controlled through close management of part placement and furnace loading. All heat treatment loads are computer controlled and monitored to assure recording of the complete history of every furnace load.

Testing Laboratory

Our in-house A2LA Accredited laboratory (ISO/IEC 17025:2017) allows us to perform a number of metallurgical evaluations and mechanical tests in-house. Metallographic analysis (macro/micro structure, grain size, cleanliness), spectrographic analysis, tensile testing, Charpy impact testing, Rockwell hardness, Brinell hardness and micro hardness (Vickers and Knoop) are all included within our scope.

Machining

Within our shop we operate approximately 35 CNC lathes, several CNC mills, manual lathes, centerless grinders and other miscellaneous finishing machines. We perform turning, threading, milling, broaching, drilling, grinding and other finish machining operations.

Thread Rolling

Our in-house thread rolling capabilities allow us to form precision screw threads from ¼” diameter, through 6” diameter.

Inspection

Critical dimensions are verified through the use of calibrated, certified thread gages, micrometers, vision systems and other special inspection devices.

Non-Destructive Examination

Our in-house NDE includes visual examination, Ultrasonic Testing, Magnetic Particle Inspection, Liquid Penetrant Inspection and PMI XRF Analysis.

Part Marking/Traceability

Low stress dot peen stampers are used to mark parts with heat lot traceability, as well as any other customer, or industry required marking. This additional marking could include: part number, PO number, ASTM designation, serial number, actual piece hardness, or API License Number (as applicable).