Description
UNC 4/40, Cap Head, Socket Screw/ Allen Bolt, High Tensile (12.9), BS 2470. Cap Screw/ Bolts
Fixaball sells all lengths of UNC 4/40, self colour, allen/ hex, socket cap screw/ bolts.
What is a socket cap screw/ bolt?
The, Socket Cap Screw/ Allen Bolt, term is used to describe a fastenerthat is either fully or partially threaded. A screw is fully threaded and a bolt is partialy threaded. Some engineers may call them screws if the person uses the shorter length range of sizes. The thread stays the same length as the fastener gets longer and the maximum length of thread is equal to 2.5 times the diameter (or thereabouts). 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. ‘Cap’ refers to the cylindrical shaped head.
Orders placed before 2pm are dispatchedsame day (Mon-Fri).
Standard, Free Delivery is Royal Mail, 2nd Class (2-5 days, most likely 2 days). For a faster delivery time, select 1st class or courier at checkout.
Please make your‘No. of Items in Pack’, ‘Length’and‘Quantity’of packs, selection from the drop down menus.
UNC 4/40, Cap Head, Socket Screw/ Allen Bolt Length Available
FT – Fully Threaded
PT – Partially Threaded
| #4-40×3/8″,(FT) SOCKET HEAD CAP SCREWS UNC SELF COLOUR (1960) |
| #4-40×1/2″,(FT) SOCKET HEAD CAP SCREWS UNC SELF COLOUR (1960) |
| #4-40×5/8″,(FT) SOCKET HEAD CAP SCREWS UNC SELF COLOUR (1960) |
| #4-40×3/4″,(FT) SOCKET HEAD CAP SCREWS UNC SELF COLOUR (1960) |
| #4-40×1″,(PT) SOCKET HEAD CAP SCREWS UNC SELF COLOUR (1960) |
High Tensile 12.9 Grade.
Available Material: Plain/ Self Colour/ Black
|
Material/ Finish |
Appearance |
Level of Corrosion Resistance |
Typical Application |
|
High Tensile Steel (12.9 Grade) |
Self-Colour (black with no surface treatment) |
Low, without further surface treatment |
– No exposure to moisture – Often Greased/ Oiled |
UNC – UNF Socket Cap Screw/ Bolt Dimensions
|
Fixaball Specialist Fixings and Fasteners UNC/UNF Hexagon Socket Cap Screws Conforming to ASME/ ANSI B18.3 1960 Series |
||||||
|
Pitch TPI |
a |
ds |
h |
j |
||
|
Diameter |
UNC |
UNF |
Max |
Max |
Max |
Nom |
|
No. 4 |
40 |
48 |
0.18 |
0.11 |
0.11 |
5/16 |
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 (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.
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.
Image is for illustrative purposes only.
