Square Bolt

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Square Bolts feature a robust four-sided head design that offers easier wrench gripping than standard hex bolts, making them ideal for blind applications, heavy machinery, or historical restoration projects where visibility is limited. Originally the industry standard before the advent of hex bolts, they are still prized in agricultural equipment and rustic architectural designs for their unique aesthetic and anti-slip properties. Manufactured to standards such as DIN 479 and ASME B18.2.1, these bolts provide a secure grip and high torque transmission. At Inconel Fasteners, we modernize this traditional design by manufacturing Square Bolts in advanced superalloys like Inconel 600, 625, 718, and Monel, ensuring they withstand extreme heat and corrosive environments while maintaining their rugged reliability.

Detailed Specifications

Size
M6 to M36 Metric 1/4” to 1-1/2″ Imperial
Length
10mm to 800mm Custom Lengths Available
Type of Threads
Metric Coarse Metric Fine UNC UNF BSW (Whitworth)
Standards & Configuration
DIN 479 (Square Head) ASME B18.2.1 (Square Bolt) ISO 887 Short / Long Dog Point
Type of Manufacturing
Hot Forging (Common) Machined Bars Milling Bars
Raw Material Origin
Indian Origin European Origin Japanese Origin US Origin Korean Origin
Finish Part Origin
Made in India Custom Origin per Request
Surface Coating
Plain / Oil Black Zinc Plated Hot Dip Galvanized (HDG) Cadmium Nickel PTFE / Teflon
Marking
Manufacturer Logo Grade ID Heat Number (Traceability)
Heat Treatment Details
Quenching & Tempering Solution Annealing Stress Relieving Normalizing
Delivery Terms
Ex-Works (EXW) FOB CIF CFR DDP
Packing Type
Carton Boxes Wooden Pallets Wooden Crates Export Worthy Packing
Payment Methods
L/C (Letter of Credit) T/T (Wire Transfer) Western Union
Certifications
ISO 9001:2015 PED 2014/68/EU MTC EN 10204 3.1
Additional Certifications
NABL Approved Lab Reports Third Party Inspection (TPI) RoHS Compliance
Mandatory & Additional Requirements
Positive Material Identification (PMI) NACE MR0175 / ISO 15156 Ultrasonic Test (UT) Intergranular Corrosion Test (IGC)

Available Inconel Grades & Standards

Dimensions Chart (DIN 479)

Nominal Size (d) Pitch (P) Width Across Flats (s)
(Max)		 Head Height (k)
(Max)		 Thread Length (b)
(L ≤ 125)
M6 1.0 10.0 mm 4.0 mm 18.0 mm
M8 1.25 13.0 mm 5.5 mm 22.0 mm
M10 1.5 17.0 mm 7.0 mm 26.0 mm
M12 1.75 19.0 mm 8.0 mm 30.0 mm
M16 2.0 24.0 mm 10.0 mm 38.0 mm
M20 2.5 30.0 mm 13.0 mm 46.0 mm
M24 3.0 36.0 mm 15.0 mm 54.0 mm
M30 3.5 46.0 mm 19.0 mm 66.0 mm
M36 4.0 55.0 mm 23.0 mm 78.0 mm

Chemical Composition (Inconel Grades)

Grade Ni (Nickel) Cr (Chromium) Fe (Iron) Mo (Molybdenum) Nb (Niobium) Co (Cobalt) Other Elements
Inconel 600 72.0% Min 14.0 - 17.0% 6.0 - 10.0% - - - Mn 1.0%, C 0.15%
Inconel 601 58.0 - 63.0% 21.0 - 25.0% Balance - - - Al 1.0 - 1.7%
Inconel 625 58.0% Min 20.0 - 23.0% 5.0% Max 8.0 - 10.0% 3.15 - 4.15% 1.0% Max Ti 0.4%, Al 0.4%
Inconel 718 50.0 - 55.0% 17.0 - 21.0% Balance 2.8 - 3.3% 4.75 - 5.5% 1.0% Max Ti 0.65 - 1.15%
Inconel X-750 70.0% Min 14.0 - 17.0% 5.0 - 9.0% - 0.7 - 1.2% 1.0% Max Ti 2.25 - 2.75%, Al 0.4 - 1.0%
Inconel 800 30.0 - 35.0% 19.0 - 23.0% 39.5% Min - - - Al 0.15 - 0.60%, Ti 0.15 - 0.60%
Inconel 825 38.0 - 46.0% 19.5 - 23.5% 22.0% Min 2.5 - 3.5% - - Cu 1.5 - 3.0%, Ti 0.6 - 1.2%

Mechanical Properties (Inconel Square Bolts)

Grade Tensile Strength
(MPa / N/mm²) Min		 Yield Strength
(MPa / N/mm²) Min		 Elongation
(%) Min		 Hardness
(HRC / HB)
Inconel 600 550 240 30% 65 - 85 HRB
Inconel 601 550 205 30% 60 - 80 HRB
Inconel 625 827 414 30% 145 - 220 HB
Inconel 718 1275 1035 12% 36 - 44 HRC
Inconel X-750 1100 700 15% 30 - 40 HRC
Inconel 800 520 205 30% 75 HRB (Max)
Inconel 825 586 241 30% 135 - 165 HB

DIN Standards for Bolts

Comprehensive list of dimensional standards for industrial fasteners.

Series 100 - 900
  • DIN 186
  • DIN 188
  • DIN 261
  • DIN 444
  • DIN 479
  • DIN 580
  • DIN 601
  • DIN 603
  • DIN 604
  • DIN 605
  • DIN 610
  • DIN 787
  • DIN 797
  • DIN 931
  • DIN 933
  • DIN 933 SZ
Nuts & Precision
  • DIN 431
  • DIN 439 A/B
  • DIN 466
  • DIN 467
  • DIN 508
  • DIN 547
  • DIN 548
  • DIN 555
  • DIN 557
  • DIN 562
  • DIN 582
  • DIN 798
  • DIN 917
  • DIN 934
  • DIN 935
  • DIN 936
  • DIN 937
Studs & Washers
  • DIN 525
  • DIN 835
  • DIN 938
  • DIN 939
  • DIN 940
  • DIN 976
  • DIN 125 A/B
  • DIN 126
  • DIN 127 A/B
  • DIN 433
  • DIN 440 R/V
  • DIN 6796
  • DIN 7980
  • DIN 9021
Extended & Heavy Series
DIN 3570
DIN 7968
DIN 7969
DIN 7990
DIN 7992
DIN 70613
DIN 70614
DIN 80705
DIN 6331
DIN 6334
DIN 6915
DIN 6924
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