Stock Forms, Types and Sizes
Most materials are produced in standard sizes enabling them to be easily used across industries. Knowing what shapes and sizes are available makes designing, buying and tooling easier. Standard components are the parts added to the materials such as bolts, screws and bindings. They are a standard size so they can be bought in from other specialist factories saving money and time.
Paper and Board:
Paper and board are available by the sheet, roll or ply.
Sheets come in standard sizes going down by halving its size each time. The biggest sheet is A0 the A1, A2, A3 to A6.
Paper and board come in different weights called GSM (grams per square metre) over 200gsm becomes board. An example would be cartridge paper, a heavy drawing paper which is around 150 gsm.
Ply is the thickness of paper or board in layers such as toilet roll.
Standard components include drawing pins, Velcro for mounting displays, treasury tags, staples and paper fasteners. Book bindings such as spiral binding, comb binding or hard backs are also components. Seal, tape and glue are also bought in, standard products. Addition of windows, inserts and stickers are all components which can be added to paper.
Timber based materials:
Planks of wood are sold in standard widths, length, diameter and thicknesses. Rough sawn wood is used for hidden building work as it hasn’t been planed smooth. Planed Square Edge (PSE) is timber which has been sent through a planer / thicknesser to create a smooth standard thickness. A router can be used to curve edges of planed timber to create mouldings such as door frames, and skirting boards available in various cross section shapes.
Manufactured board has the advantage of boing available in much bigger sheets than planks of wood. They usually are 2440mm x 1220mm or 1220mm x 610mm sheets in a variety of thicknesses. Standard components are hinges, screws, bolts, handles and KD fittings. KD (Knock Down) fittings allow wood or board to be joined together quickly and accurately, particularly used in flat pack furniture. Examples are blocks, dowels, scan fittings and CAM locks.
Metal based materials:
Metal is available in sheet or tubular form, usually in standard thickness, length or diameter. It is difficult and expensive to reform metal so ordering the right sized tube, rod, square or hexagonal tube,angle, bar or rod is a good starting point for production. Cost can be worked out by length from a good design drawing. Different cross sectioned bars are available.
Wire of different widths are also available in stock thicknesses and a variety of material. Copper, steel, aluminium etc.
Standard components which can be used to join metal are nuts, bolts, rivets and screws which are cast into moulds.
Like metal and timber polymers come in a range of stock sizes, rod, sheet and tubes. It can also be bought in granules, pellets and powder for moulding. It can also be blown into foam and heated and rolled into film. Granules and powders can be melted and moulded easily into non stock shapes. Standard components are screws, nuts, bolts, rivets and adhesives.
Textiles based materials:
Fabrics are available in rolls in standard widths, usually 90, 115 and 150cms. It is also available in different weights made by how tight the fabric is knitted or woven or how thick the fibres are.
Fibres are usually rolled together to increase thickness, this is called ply so would be called 1 ply, 2 ply etc. Knitwear thickness is measured in denier.
Standard components are often fastenings such as buttons, zips, Velcro, press studs and hooks and eyes. They can also be decorative such as rivets, embroidered patches and sequins.
Electrical and mechanical components:
Standard components for electrical systems are generally sold by the number, volt or current rating.
Resistors are most common in the E12 series meaning they have 12 values of resistance. Coloured bands identify the different values, there are always 4 coloured bands on E12 resistors.
Dual in line integrated circuit packages (DIL) are tiny circuits within a single component. The circuit is inside a plastic or ceramic case with pin legs which attach it to the circuit board. Each pin has a number to be able to pinpoint which pin does which function. Micro controllers are programmable integrated circuits (PICS), some can only be programmed once and are bought in by manufacturers pre-programmed whilst others can be reprogrammed as advancements are made. The more information on a PIC the more it would cost. Surface Mount Technology (SMT) is a method for producing electronic circuits onto PCB’s with through hole components that slot into place.
Units of electrical measurements:
Units of current (amp)
Unit of resistance (ohm)
Unit of potential difference (volt)
Mechanical components are such things as chains, gears, sprockets and springs.