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Know Your Screws

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The range of screws and fasteners is vast, this document concentrates on the most common types that would be used in hobbies and D.I.Y projects.
Metric Machine Screws
In general the length of a screw is taken from the surface of the material you are fixing to the point/end of the screw. Keep an eye on the 'L' in each of these drawings.
Screw Diameters are shown as an M No, M=Metric No=d on drawings. M2, M2.5, M3, M3.5, M4, M5, M6, M8.
Length (L): 3mm to 100mm. Length is related to diameter so for example you cannot get an M8 at 3mm.
Material:  Brass, Steel, A4 Stainless Steel, A2 Stainless Steel.
Colour:    Self Colour, Zinc Trivalent Clear, Zinc & Black, Zinc & Yellow.
         Head Pozidrive *                        Countersunk Pozidrive  *                   Pan Head T Drive                          Countersunk T Drive
        Pan Head Recess H                         Countersunk Recess H                         Raised Countersunk Pozidrive
  Slotted Pan Head *                     Slotted Countersunk                           Slotted Cheese Head                   Slotted Raised Countersunk
Self Tapping Screws
Self Tapping Screws generally come in 2 ranges Pointed, Blunt End. We are concentrating on the pointed screws, and the same principle of length (L) applies as above.
However Screw size notification differs as the screw diameter is given as a Number, the higher the number the bigger the diameter.
Screw Diameter: No2 (2.2mm), No4 (2.9mm), No6 (3.5mm), 3.9mm, No8 (4.2mm), No10 (4.8mm), No12 (5.5mm), No14 (6.3mm)
Length (L): 4.5mm to 75mm
Material: A2 Stainless Steel, A4 Stainless Steel, Steel.
Colour:   Zinc & Yellow De-embrittled, Zinc & Black De-embrittled, Self Colour, Zinc Trivalent, Clear De-embrittled.
  Head Pozidrive  *                     Pan Head Recess H                         Pan Head Slotted  *                            Countersunk Pozidrive *
  Countersunk Recess H                     Countersunk Slotted               Raised Countersunk Pozidrive    Raised Countersunk Recess H
          Counterunk Slotted                Flange Head Pozidrive                            Hexagon Head                           Pan Head T Drive
     Countersunk T Drive                      Washer Hexagon Head
The * screws are all ex-stock, the rest are to order, with delivery times from 4 days to 2 weeks depending on structure.
Due to the fact that fastening applications differ greatly, the below information is for guidance only and is correct to the best of our knowledge. The customer must satisfy themselves with the performance of the fastener and validity of the data. Brimal will not be held responsible for any failure that may occur from the use of this information