Countersunk Bolts

Countersunk bolts, also known as Flat Head Hex Socket Bolts or Flat Head Socket Cap Bolts, are precision-engineered fasteners with a flat head and conical neck designed for flush surface installations. Manufactured in both metric and imperial sizes, they are available in UNC, UNF, UN, and ISO thread profiles. At Adfast Component, we produce Countersunk Bolts in a wide range of materials and grades including ASTM F568 (Grades 8.8, 10.9, 12.9), F593, SS304, SS316, and Duplex 2205. Explore our offerings for details on dimensions, thread types, torque values, and manufacturing standards.

Countersunk Bolts
Countersunk Bolts Properties
Countersunk Bolts Standards
Countersunk Bolts Materials
FormingHot & Cold Forged
Metric SizeM10 to M100
Imperial Size3/8 to 8″
ThreadsUNC, UNF, ISO, BSW & ACME.
StandardsASME,BS,DIN,ISO,UNI,DIN-EN
Sub types1. Fully Threaded Countersunk Bolts
2. Partial Threaded Countersunk Bolts
3. Metric Countersunk Bolts
4. Imperial Countersunk Bolts
ASME B18.2.1 3/8 inch to 3 inch
BS 1769 ½ inch to 2 inch
ASME B18.2.3.6M M12 to M36
ASME B18.2.3.7M M16 to M36
DIN 6914 M12 to M36
ISO 7412 M12 to M36
UNI 5712 M12 to M36
DIN-EN 14399-4 M12 to M36
Carbon Steel FastenersAlloy Steel FastenersStainless Steel Fasteners
Duplex Steel FastenersSuper Duplex Stainless Steel FastenersZeron 100 Fasteners
Nitronic FastenersFerralium FastenersNickel Alloy Fasteners
Inconel FastenersIncoloy FastenersMonel Fasteners
Hastelloy FastenersNimonic FastenersCopper Nickel Fasteners
Silicon Bronze FastenersAluminium Alloy FastenersBerylium Copper Fasteners
Aluminum Bronze FastenersPhosphor Bronze FastenersTitanium Fasteners
Tantalum FastenersZirconium FastenersCobalt Alloy Fasteners
Maraging Steel FastenersStellite FastenersMolybdenum Fasteners

Countersunk Bolts Specifications

B5B6B7
B7MB16B8
B8 class 1B8 class 2B8 class 2B
B8AB8CB8C class 1
B8C class 2B8CAB8CLN
B8CLN class 1B8CLN class 1DBCLNA
B8LNB8LN class 1B8LN class 1D
B8LNAB8MB8M class 1
B8M class 2B8M2B8M3
B8MAB8MLCuNB8MLCuN Class 1B
B8MLCuN Class 1DB8MLCuN Class 2B8MLCuNA
B8MLNB8MLNAB8MN
B8MN Class 1BB8MN Class 1DB8MN Class 2
B8MNAB8NB8N Class 1B
B8N Class 1DB8N Class 2B8NA
B8PB8PAB8R
B8R Class 1CB8R Class 1DB8RA
B8SB8SAB8T
B8T Class 1B8T Class 2B8TA
Grade AGrade B 
L7L7ML43
B8B8MB8T
B8C  
Type 1Type 2Type 3
Grade BCGrade BD 
Type 1Type 2 
Grade 660Grade 651Grade 662
Grade 665Grade 668 
Type 1Type 2Type 3
Grade B21Grade B22Grade B23
Grade B24Grade B24V 
Grade 36Grade 55Grade 105