Socket Screw/ Allen Bolt, Cap Head

Here at Fixaball, we stock all sizes and lengths at the best internet prices and free delivery

Orders placed before 2pm are usually dispatched same day (Mon-Fri).

The, ‘Socket Screw/ Allen Bolt,’ term is used to describe a fastener that is partially threaded in lengths over 1 inch; generally speaking (they can vary up to 12mm with different diameters). The space of unthreaded area confirms that the fastener is a bolt. Some engineers may call them screws if the person only uses the shorter length range of sizes, under an inch. ‘Socket,’ refers to the hexagon shaped indentation found on the top of the fasteners’ head. Here, you can use a hexagon key (Allen Key) to tighten and loosen the fastener.

They are available in the following head types:

  • Cap Head
  • Countersink Head
  • Button Head
  • Flange Button Head
  • Grub 
  • Shoulder - Cap Head

They are available in the following materials (please note; not every head type is available in every material):

Material/ Finish

Appearance

Level of Corrosion Resistance

Typical Application

High Tensile Steel

Self-Colour (black with no surface treatment)

Low, without further surface treatment

-          No exposure to moisture

-          Often Greased/ Oilied

High Tensile Steel - Zinc

Bright Shine – Blue to Yellow

Internal

-          Low exposure to moisture

High Tensile Steel -Galvanised

Textured, dull - metallic tones

External

-          Constant Weathering

-          Chemical exposure

A2 Stainless Steel

Dull Shine

External

-          Intermittent weathering

-          Hygiene

A4 Stainless Steel

Dull Shine

External

-          Constant Weathering

-          Chemical exposure

Nylon

Off white

High

-          provide electrical insulation.

-          Low weight

-          Minimal load

 

UNITS OF MEASUREMENT FOR THREAD TYPES

Metric Coarse and Metric Fine

Are in Millimetre (mm) units and were developed to simplify the imperial systems. Europe moved to this system but the Americans choose Imperial as their default. A coarse thread has less helical coils per mm and a fine one has more. Coarse is used for heavier loads and fine is used for lighter loads prone to vibrations.

 

British Association (BA)

screw threads, named after the British Association for Advancement of Science, were devised in 1884 and standardised in 1903. Screws were described as "2BA", "4BA" etc., BA threads are specified by British Standard BS 93:1951 "Specification for British Association (B.A.) screw threads with tolerances for sizes 0 B.A. to 16 B.A." They are associated with metric units of measurement.

 

British Standards Brass (BSB)

Is a specialist thread form based upon the Whitworth thread and consisting of 26 threads per inch (imperial) whatever the thread diameter.

British Standard Cycle Thread (BSC)       

BSC Thread has extra fine threads 26 TPI originally for use on bicycles and motorcycles. The thread runs at a 60 degree rather than a 55 degree angle.

British Standard Fine (BSF)       

A thread form based upon the British Standard Whitworth form but with a finer thread; more threads per inch and has the same thread angle as the BSW and smaller thread depth.

BSF was developed by R E B Crompton and his assistant George Field and was first introduced in 1908, the thread form is specified in BS 84: 1956

British Standard Whitworth (BSW)

A thread form developed by Sir Joseph Whitworth in 1841. The thread form has rounded roots and crests, a thread angle of 55 degrees, the thread form is specified in BS 84: 1956

 

UNIFIED THREAD STANDARDS 

The basic American standards for fastening screw threads as agreed upon by standard bodies of Canada, the United Kingdom, and the United States. They are a complete and integrated system of threads for fastening purposes. Their outstanding characteristic is general interchangeability of threads achieved through the standardization of thread form, diameter-pitch combinations, and limits of size

 

Unified National Coarse (UNC)     

is a thread form with a 60 degree flank angle rounded roots and flat crests. For a given diameter it has a larger thread pitch than an equivalent diameter UNF thread. The unified thread is based on inch sizes and was first standardised in 1948 unifying the Whitworth and American standard thread forms

Unified National Extra Fine (UNEF) 

is a Unified thread form with a very fine (small) pitch that are typically used on instruments and parts requiring a fine adjustment.

Unified National Fine (UNF)

is a thread form with a 60 degree flank angle rounded roots and flat crests. For a given diameter it has a smaller thread pitch than an equivalent diameter UNC thread.

Unified National (UN)

thread form with a rounded root contour, applies only to external threads. (The UN thread form has a flat, or optionally, a rounded root contour.) The majority of fasteners with a Unified thread form (UNC UNF) have a rounded root contour i.e. are UNR threads.

 

 

Socket Screw, Cap Head

0BA, Cap Head, Socket Screw (12.9).
0BA, Cap Head, Socket Screw/ Allen Bolt, High Tensile (12.9), Self Colour. Fixaball sells all sizes and lengths of 0BA...
from £6.17
2BA, Cap Head, Socket Screw (12.9).
2BA, Cap Head, Socket Screw/ Allen Bolt, High Tensile (12.9), Self Colour. Fixaball sells all sizes and lengths of 2BA...
from £3.85
4BA, Cap Head, Socket Screw (12.9).
4BA, Cap Head, Socket Screw/ Allen Bolt, High Tensile (12.9), Self Colour. Fixaball sells all sizes and lengths of BA...
from £3.50
6BA, Cap Head, Socket Screw (12.9).
6BA, Cap Head, Socket Screw/ Allen Bolt, High Tensile (12.9), Self Colour. Fixaball sells all lengths of 6BA cap screws...
from £1.50
BSF, 1", Cap Head, Socket Screw (12.9).
BSF, 1", Cap Head, Bolt/ Socket Screw/ Allen Bolt/, High Tensile (12.9), BS 2470. Here at Fixaball, we stock all sizes...
from £26.99
BSF, 1/2", Cap Head, Socket Screw (12.9).
BSF, 1/2", Cap Head, Bolt/ Socket Screw/ Allen Bolt/, High Tensile (12.9), BS 2470. Fixaball.co.uk sells all lengths of BSF, 1/2" cap...
from £5.35
BSF, 1/4", Cap Head, Socket Screw (12.9).
BSF, 1/4", Cap Head, Bolt/ Socket Screw/ Allen Bolt/, High Tensile (12.9), BS 2470. Fixaball.co.uk sells all lengths of BSF, 1.4" cap...
from £2.96
BSF, 3/16", Cap Head, Socket Screw (12.9).
BSF, 3/16", Cap Head, Bolt/ Socket Screw/ Allen Bolt/, High Tensile (12.9), BS 2470. Here at Fixaball, we stock all sizes...
from £5.13
BSF, 3/4", Cap Head, Socket Screw (12.9).
BSF, 3/4", Cap Head, Bolt/ Socket Screw/ Allen Bolt/, High Tensile (12.9), BS 2470. Here at Fixaball, we stock all sizes...
from £11.73
BSF, 3/8", Cap Head, Socket Screw (12.9).
BSF, 3/8", Cap Head, Bolt/ Socket Screw/ Allen Bolt/, High Tensile (12.9), BS 2470. Fixaball.co.uk sells all  lengths of BSF 3/8", cap...
from £6.36
BSF, 5/16", Cap Head, Socket Screw (12.9).
BSF, 5/16", Cap Head, Bolt/ Socket Screw/ Allen Bolt/, High Tensile (12.9), BS 2470. Fixaball.co.uk sells all lengths of BSF 5/16" cap...
from £2.64
BSF, 7/16", Cap Head, Socket Screw (12.9).
BSF, 7/16", Cap Head, Bolt/ Socket Screw/ Allen Bolt/, High Tensile (12.9), BS 2470. Fixaball.co.uk sells all lengths of BSF, 7/16" cap...
from £2.79
BSW- Whitworth, 1" X 5", Cap Head, Socket Screw.
BSW- Whitworth, 1" X 5", Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), BS 2470. Here at Fixaball, we...
£25.31
BSW- Whitworth, 1/2", Cap Head, Socket Screw.
BSW- Whitworth, 1/2", Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), BS 2470. Fixaball.co.uk sells all lengths of 1/2" Whitworth...
from £3.21
BSW- Whitworth, 1/4", Cap Head, Socket Screw.
BSW- Whitworth, 1/4", Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), BS 2470. Here at Fixaball, we stock all...
from £1.56
BSW- Whitworth, 3/16", Cap Head, Socket Screw.
BSW- Whitworth, 3/16", Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), BS 2470. Here at Fixaball, we stock all...
from £2.79
BSW-Whitworth, 3/4" X 1", Cap Head, Socket Screw.
BSW- Whitworth, 3/4" X 1", Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), BS 2470. Here at Fixaball, we...
from £9.07
BSW-Whitworth, 3/8", Cap Head, Socket Screw.
BSW-Whitworth, 3/8", Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), BS 2470. Fixaball.co.uk sells a great range of...
from £2.66
BSW-Whitworth, 5/16", Cap Head, Socket Screw.
BSW-Whitworth, 5/16", Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), BS 2470. Here at Fixaball, we stock all sizes...
from £2.79
BSW-Whitworth, 5/8", Cap Head, Socket Screw.
BSW-Whitworth, 5/8", Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), BS 2470. Here at Fixaball, we stock all sizes...
from £3.49
BSW-Whitworth, 7/16" x 3/4", Cap Head, Socket Screw.
BSW-Whitworth, 7/16" x 3/4", Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), BS 2470. Here at Fixaball, we stock...
from £4.95
M1.6 M2 M2.5, Cap Head, Socket Screw (12.9).
M1.6, M2, M2.5, Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), DIN 912, Cap Screw. Fixaball.co.uk sells all...
from £2.30
M10 x 1 P, Cap Head, Socket Screw, (12.9).
M10 x 1 Pitch Thread (super-fine), Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), DIN 912, Cap Screw. Fixaball.co.uk sells...
from £4.09
M10 x 1.25 P, Cap Head, Socket Screw, (12.9).
M10 x 1.25 Pitch Thread (fine), Cap Head, Bolt/ Socket Screw/ Allen Bolt, High Tensile (12.9), DIN 912, Cap Screw....
from £2.99