RAYCHIN LIMITED, we are materials experts who focus only on fasteners made from the highest performance specialty metals for the most challenging and extreme applications.

• Stainless Steel Series: Martensitic Stainless Steel, Ferritic Stainless Steel, Austenitic Stainless Steel, Austenitic-Ferritic (Duplex) Stainless Steel and Precipitation Hardening Stainless Steel.

• Super Alloys Series: Nickel-based Alloy, Cobalt-based Alloy, Iron-based Alloy, Molybdenum-based Alloy, ‌Titanium-based Alloy, Copper based Alloy, ‌Zirconium Alloy.

• Alloy Steel Series: Low Alloy Steel, Medium Alloy Steel, High Alloy Steel, Special Alloy Steel.

Square Bolts | Square Head & Lag Bolts in Special Alloys | RAYCHIN Manufacturer

RAYCHIN manufactures square bolts in 25+ alloys including 17-4PH, Monel, Titanium & Duplex Steel. Square head bolts, lag bolts & custom square fasteners compliant with ASME, DIN, ISO, ASTM standards. Global supplier for construction, marine & industrial applications.

Square Bolts for High-Torque & Anti-Rotation Applications

RAYCHIN is a specialized manufacturer of high-performance square bolts (commonly called square head bolts, lag bolts, or carriage bolts)—fasteners featuring a four-sided head designed for secure wrenching in confined spaces and applications requiring significant torque application. These robust fasteners provide excellent anti-rotation characteristics and are engineered from over 25 advanced alloys to meet demanding requirements in marine construction, heavy machinery, railroad, mining, and historical restoration industries worldwide.

Square Bolt Types & Classifications

We manufacture comprehensive square bolt configurations to address diverse industrial needs:

1. Standard Square Bolts:

• Square Head Bolts: Traditional bolts with four-sided heads for wrenching, manufactured to ASME B18.5, DIN 479, ISO 2725-1, and JIS B1186 standards.

• Square Head Lag Bolts (Lag Screws): Featuring wood threads for direct installation into timber, compliant with ASME B18.2.1, ASTM A307, and DIN 571 specifications.

• Square Neck Carriage Bolts: Combination of square head with smooth domed top and square neck that prevents rotation in wood applications per ASME B18.5, DIN 603.

2. Special Application Square Bolts:

• Square Head Shoulder Bolts: Combine square head with precision shoulder for machinery alignment and pivoting mechanisms.

• Square Head Set Screws: Fully threaded square head bolts for adjustment applications and securing collars.

• Square Head Plow Bolts: Feature countersunk square heads for agricultural equipment and earth-moving machinery.

• Custom Square Head Designs: Manufactured to exact OEM specifications with non-standard dimensions, special threads, and unique configurations.

Material Grades & International Standard Specifications

Our square bolts are precision-engineered from the following advanced material systems with full international standard compliance:

1. Precipitation-Hardening Stainless Steels:

• 17-4 PH (UNS S17400): Supplied to ASTM A564 Type 630, AMS 5643, DIN 1.4542 in H900, H1025, H1150 tempers for high-strength marine square head bolts.

• PH 13-8 Mo (UNS S13800): Manufactured per ASTM A564 Type 625, AMS 5629 for superior corrosion resistance.

2. Nickel-Based Superalloys:

• Inconel® Alloys: Inconel 718 (UNS N07718/AMS 5663), Inconel 625 (UNS N06625/ASTM B446), Inconel 600 (UNS N06600) for high-temperature industrial applications.

• Monel® Alloys: Monel K500 (UNS N05500/AMS 4676), Monel 400 (UNS N04400) for marine hardware and offshore square bolts.

• Hastelloy® Alloys: Hastelloy C276 (UNS N10276/ASTM B574), C22 (UNS N06022), B2 (UNS N10665) for severe chemical processing environments.

• Waspaloy (UNS N07001): Per AMS 5708, AMS 5824 for aerospace and high-temperature applications.

• Nimonic® Series: Nimonic 80A (UNS N07080), Nimonic 90 (UNS N07090) compliant with BS HR 501/502 standards.

3. Duplex & Super Duplex Stainless Steels:

• Duplex Steel: Duplex 2205 (UNS S32205) to ASTM A193 B8S, EN 1.4462 specifications for offshore platform square bolts.

• Super Duplex Alloys: Alloy 926 (UNS N08926), AL-6XN® (UNS N08367) meeting ASTM A193 B8S, NACE MR0175.

4. Titanium Alloys:

• Grade 5 Titanium (Ti-6Al-4V): UNS R56400 per AMS 4928, ASTM F467 for lightweight, high-strength applications.

• Grade 2 Titanium: UNS R50400 to ASTM B348, AMS 4921 for marine grade square head bolts.

5. Refractory & Exotic Metals:

• Tantalum (UNS R05200): ASTM B365, AMS 7845 for chemical processing square bolts.

• Zirconium 702 (UNS R60702): ASTM B550, ASME SB550 for acid applications.

• Molybdenum (UNS R03600) & Tungsten: For extreme temperature and wear applications.

6. Specialty Alloys:

• Nitronic® Alloys: Nitronic 60 (UNS S21800), Nitronic 50 (UNS S20910) to ASTM A193 B8N for high-strength, galling-resistant applications.

• High-Performance Stainless: 254 SMO (UNS S31254/EN 1.4547), 310SS (UNS S31000), Alloy 20 (UNS N08020), Alloy 330 (UNS N08330).

• Cobalt Alloys: MP35N (UNS R30035/AMS 5844), MP159 (AMS 5846) for ultra-high strength mining bolts.

• Iron-Based Superalloy: A286 (UNS S66286) to AMS 5731, ASTM A453 Grade 660.

7. Aluminum Alloy:

• Aluminum 7075 (UNS A97075): AMS QQ-A-225/9, ASTM F467 in T6, T73 tempers for lightweight structural bolts.

8. Pure Nickel & Incoloy:

• Nickel 200 (UNS N02200): ASTM B160, ASME SB160.

• Incoloy® Alloys: Incoloy 825 (UNS N08825), Incoloy 925 (UNS N09925).

Custom Square Bolt Manufacturing Services

RAYCHIN provides complete custom square bolt manufacturing from your technical specifications:

• Standards Compliance: ASME B18.5, DIN 479, ISO 2725, ASTM A307, BS 1768, and customer drawings.

• Special Features: Square neck designs, shoulder sections, special threads, heat-treated sections, corrosion-resistant coatings.

• Surface Treatments: Hot-dip galvanizing, mechanical plating, XYLAN coatings, passivation, electropolishing.

• Full Processing: Hot forging, CNC machining, thread cutting/rolling, heat treatment, surface finishing.

• Quality Assurance: Complete MTRs (EN 10204 3.1), mechanical testing, coating thickness verification, compliance with ISO 9001, CE marking, NACE standards.

Industry Applications

• Marine & Offshore: Dock construction, shipbuilding, offshore platforms (ABS, DNV, LR certified)

• Heavy Construction: Bridge construction, structural steelwork, timber framing

• Railroad & Transportation: Track fastening, rolling stock, railway infrastructure

• Mining & Mineral Processing: Equipment assembly, conveyor systems, crusher machinery

• Agricultural Machinery: Tractor attachments, implement manufacturing, harvesting equipment

• Historical Restoration: Period-accurate fasteners for heritage buildings and vintage equipment

Why Choose RAYCHIN?

• Material Expertise: 25+ years experience with heavy-duty square bolts in exotic alloys

• Forging Specialization: Hot forging capabilities for large square head bolts

• Industry Certifications: Products meet ASTM, DIN, ISO, JIS, BS standards

• Custom Engineering: Design optimization for specific application requirements

• Global Standards: Compliance with international construction and marine standards

• Global Supply: Reliable supplier to North America, Europe, Asia-Pacific, Middle East markets

Request Square Bolt Quotation
Contact RAYCHIN for engineering consultation and competitive pricing. Submit your drawings for square head bolts, lag bolts, or custom square fasteners.

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