Inconel Fasteners Inc.

Square Nuts are four-sided fasteners designed for specific heavy-duty and blind-spot applications where a standard hex nut would be difficult to wrench. Their unique square geometry provides a greater surface area in contact with the part, offering superior resistance to loosening from vibration and allowing them to sit flush in square channels or recesses (locking them in place for one-handed tightening). Manufactured to standards like DIN 557, DIN 562, and ASME B18.2.2, these nuts are favored in rail, electrical transmission, and furniture industries. At Inconel Fasteners, we produce Square Nuts from high-performance alloys like Inconel 600, 625, ensuring they resist oxidation and galvanic corrosion in harsh outdoor or high-temperature environments.

Detailed Specifications

Size Range

M4 to M64 Metric 1/4” to 3″ Imperial

Nut Style & Geometry

Chamfered Square (DIN 557) Flat Square (DIN 562) Heavy Square (ASME B18.2.2)

Type of Threads

Metric Coarse Metric Fine UNC (Coarse) UNF (Fine) BSW

Threads Configuration

ASME B1.1 Class 2B ISO 261 (6H Tolerance) ISO 965

Type of Manufacturing

Machined from Square Bar Hot Forging Cold Forging Milling

Raw Material Origin

Indian Origin European Origin Japanese Origin US Origin

Finish Part Origin

Made in India

Surface Coating

Plain / Oil Black Zinc Plated Hot Dip Galvanized (HDG) PTFE / Xylan Passivation

Marking

Manufacturer Logo Material Grade (e.g., 625) Heat Code

Heat Treatment Details

Solution Annealing Stress Relieving Age Hardening

Delivery Terms

Ex-Works (EXW) FOB CIF DDP

Packing Type

Heavy Duty Carton Wooden Crates VCI Bags

Payment Methods

L/C (Letter of Credit) T/T (Wire Transfer)

Certifications

ISO 9001:2015 MTC EN 10204 3.1 NACE MR0175

Additional Certifications

NABL Lab Reports Third Party Inspection (TPI)

Mandatory Requirements

Positive Material Identification (PMI) Dimensional Inspection Visual Thread Check

Dimensions Chart (DIN 557 Square Nut)

Nominal Size (d)	Pitch (P)	Width Across Flats (s) (Wrench Size)	Nut Height (m) (Max)	Width Across Corners (e) (Min)
M5	0.8	8 mm	4.0 mm	11.3 mm
M6	1.0	10 mm	5.0 mm	14.1 mm
M8	1.25	13 mm	6.5 mm	18.4 mm
M10	1.5	17 mm	8.0 mm	24.0 mm
M12	1.75	19 mm	10.0 mm	26.9 mm
M16	2.0	24 mm	13.0 mm	33.9 mm
M20	2.5	30 mm	16.0 mm	42.4 mm
M24	3.0	36 mm	19.0 mm	50.9 mm

Chemical Composition (Standard Grades)

Grade	Ni (Nickel)	Cr (Chromium)	Fe (Iron)	Mo (Molybdenum)	Nb (Niobium)	Cu (Copper)	Other Elements
Inconel 600	72.0% Min	14.0 - 17.0%	6.0 - 10.0%	-	-	0.5% Max	Mn 1.0%
Inconel 625	58.0% Min	20.0 - 23.0%	5.0% Max	8.0 - 10.0%	3.15 - 4.15%	-	Al 0.4% Max
Inconel A286 (Gr. 660)	24.0 - 27.0%	13.5 - 16.0%	Balance	1.0 - 1.5%	-	-	Ti 1.9-2.3%, V 0.1-0.5%
Inconel 825	38.0 - 46.0%	19.5 - 23.5%	22.0% Min	2.5 - 3.5%	-	1.5 - 3.0%	Ti 0.6 - 1.2%
Inconel 718	50.0 - 55.0%	17.0 - 21.0%	Balance	2.8 - 3.3%	4.75 - 5.5%	-	Ti 0.65 - 1.15%

Mechanical Properties (Square Nuts)

Grade	Tensile Strength (MPa / N/mm²) Min	Yield Strength (0.2% Offset) Min	Elongation (%) Min	Hardness (HRC / HB)
Inconel 625	827	414	30%	145 - 220 HB
Inconel 600	550	240	30%	65 - 85 HRB
Inconel A286 (Gr. 660)	895 - 1000	585 - 750	15%	24 - 35 HRC
Inconel 718	1275	1035	12%	36 - 44 HRC
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