Bolts, Screws and Fixings used for DIY Loudspeakers
Amongst the vast number of available fixings, QTA systems have selected a few types which are useful for Loudspeaker construction. Most popular are screws but depending upon cabinet material and access, bolts may be better. MDF, the material of choice? is constructed from pressed wood fibres. It is easily split when screwing into it's edges and needs pilot holes. In addition, the faces have a hard surface layer which is difficult to screw into without pilot holes. Repeated use of screws can strip the wood leaving useless holes. Bolts compress the material but need rear fitting access or the use of accurately aligned wood inserts. So.........Choose carefully. View here our full range of Bolts, Screws and Fittings
Wood Screws Pan Head. Mild steel. Better grades are case-hardened and have hard tips. Available in cross-slot and / or Pozidrive / Phillips heads. Finish is usually Bright Zinc Plated, known as a BZP finish. Other options include Chemi and Oil finish, known as Chemi-Blacked. Types known as Japanned screws have a spray lacquer finish which is baked and subsequently polished to give a shiny appearance. These are usually of mild steel hence soft and only available as a slotted head type. The lacquered finish is easily chipped off and so are not suitable for repeated use if you want to retain their finish.
Pan Head Machine Screws Mild Steel. Pan Head Screws, plated (BZP) and fully threaded. Pozidrive head. Many other varieties are available in different materials including Stainless Steel and Brass.
Button Head Bolts Usually High Tensile steel or Stainless steel, often supplied in self colour. The heads have a hexagonal recess which requires an Allen key or hexagon Bit to tighten. Some are available with Chemi-Black finish. Note: Chemi-black finish is a 'cosmetic finish'. In a damp environment it WILL eventually corrode.
Cap Head Bolts Same material toughness as Button Heads, Note: Bolts usually have (20 - 25)mm threaded body length only. If you find you need a longer thread, carefully select the correct Bolt length. Bolts with a fully threaded body are known as SET Screws, NOT Bolts. Also available in a variety of materials and finishes.
Nylon Screws: useful for fitting Air Cored and Ferrite Cored Inductors without influencing their magnetic properties. They have only moderate strength, and should not be over-tightened as they will stretch. Available with Washered Nuts i.e. integral nut and washer or with separate washers and nuts.
Washers Two basic types, Plain and Shakeproof. Plain washers can be of type A or B. This defines the outside diameter relative to the internal diameter. Type B have greater load-spreading ability because they are larger in overall diameter so..... But not here. Subsets of Shakeproof are Spring, Crinkle and Wavy. Wavy washers are only available in Stainless Steel. Crinkle can be defined as Internal or External which defines the location of the teeth. We have internal. See the Picture.......... There are many others but......