Drill bits

Twist drill
Twist bits are probably the most common drilling tools used with either a hand or electric drill. The front edges cut the material and the spirals along the length remove the debris from the hole and tend to keep the bit straight.

They can be used on timber, metal, plastics and similar materials. Most twist bits are made from either:

• 'high speed steel' (HSS), these are suitable for drilling most types of material, when drilling metal the HSS stands upto the high temperatures.
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• 'carbon steel', these bits are specially ground for drilling wood and should not be used for drilling metals, they tend to be more brittle, less flexible than HSS bits.

Twist drills are usually available in sizes 0.8-12 mm plus. They are designed for drilling relatively small holes, they sometimes tend to clog quickly especially when the wood is 'green' so when drilling deep holes (especially in hardwood) the bits should be withdrawn regularly to remove the waste.

Special care is required when using the smallest sizes since these bits are thin and brittle. Always hold the drill square to the work and apply only light pressure when drilling.

Sharpening - use a drill sharpener, a grindstone jig or an oilstone.

What is stainless steel?

WHAT IS STAINLESS STEEL?
Stainless steel is the basic name for different type of steels used primarily because of their
corrosion resistance.

All Stainless steels contains a percentage of Chromium added approx (10.5%), other material like nickel and molybdenum are also added to improve corrosion resistance.

The chromium in the stainless steel has a great affinity for oxygen, and will form a film of chromium oxide on the surface of the steel at a molecular level. The film itself is extremely thin, about 130 Angstroms and one Angstrom is one millionth of a centimetre. This layer is described as passive (does not react or influence other materials), tenacious (clings to the layer of steel and is not transferred elsewhere) and self-renewing if damaged, more chromium from the steel will be exposed to the air and form more chromium oxide.

This means that over a period of years a stainless steel knife can literally be worn away by daily use and will still remain stainless. see link.

TYPES OF STAINLESS STEEL

FERRITIC stainless steels are magnetic, have a low carbon content and contain chromium as the main alloying element, typically between 13% and 17%.They are not hardenable by heat treatment.

MARTENSITIC stainless steels are magnetic, containing typically 12% chromium with a higher carbon content than the ferritic types. They are hardenable by quenching and tempering like plain carbon steels and find their main application in cutlery, aerospace and general engineering.

AUSTENITIC stainless steels are non-magnetic and, in addition to chromium typically around 18%, contain nickel. This enhances their corrosion resistance and modifies the structure from ferritic to austenitic. They are the most widely used group of stainless steels. They are not hardenable by heat treatment.

DUPLEX stainless steels are used where combinations of higher strength and corrosion resistance are needed. They have a mixed structure of austenite and ferrite, hence the term "duplex". They are not hardenable by heat treatment.

PRECIPITATION HARDENING stainless steels, like the martensitic types, can be strengthened (ie hardened) by heat treatment. The mechanism is metallurgically different to the process in the martensitic types. This means that either martensitic or austenitic precipitation hardening structures can be produced.

How Aluminium is produce

The process of extracting Aluminium from Bauxite consumes alot of energy, so please help to recycle it. See Link for more information.

Passivating

PASSIVATING
Stainless steel pieces which have been machined or may have surface contamination from some other source can be passivated in a nitric acid solution to prepare them for plating

Powder Coating

POWDER COATING
Powder coating is an advanced method of applying a decorative and protective finish to a wide range of materials and products that are used by both industries and consumers. The powder used for the process is a mixture of finely ground particles of pigment and resin, which is sprayed onto a surface to be coated. The charged powder particles adhere to the electrically grounded surfaces until heated and fused into a smooth coating in a curing oven. The result is a uniform, durable, high-quality, and attractive finish. Powder coating is the fastest-growing finishing technology in North America, representing over 10% of all industrial finishing applications.

Powder coating gives consumers, Businesses, and industry one of the most economical, longest-lasting, and most color-durable quality finishes available.
Powder coated surfaces are more resistant to chipping, scratching, fading, and wearing than other finishes. Color selection is virtually unlimited with high and low gloss, metallic, and clear finishes available. And colors stay bright and vibrant longer. Texture selections range from smooth surfaces to a wrinkled or matte finish, and rough textures designed for hiding surface imperfections.

Electroless Nickel Plating

ELECTROLESS NICKEL PLATING
Electroless nickel produces an alloy with truly unusual properties. These properties have made EN very useful in a broad range of functional applications. Most applications take advantage of the hardness, lubricity, corrosion resistance, electrical and magnetic properties of electroless nickel, as well as its ability to cover complex geometry's and internal as well as external surfaces.

Vespel

Vespel® is a high performance polyimide material which is formed from resin manufactured only by DuPont. Polyimide materials are characterized by a ring-shaped molecular structure containing Nitrogen.

Vespel® is one of the highest performing engineering plastics currently available. Vespel® will not melt and can operate continuously from cryogenic temperatures to 550°F (288°C), with excursions to 900°F (482°C). Vespel® parts consistently exhibit superior performance in a variety of applications requiring low wear and long life in severe environments.

Vespel ® SP-1
Vespel ® SP-1 is the unfilled base resin grade. SP-1 provides maximum physical strength, elongation, and toughness as well as the best electrical and thermal insulation values. Typical applications include spacers, high-temp fixtures, valve seats, balls, gaskets, insulators, and seals.

Vespel ® SP-21
Vespel ® SP-21 has 15% graphite by weight added to the base resin for increased wear resistance and reduced friction in applications such as bearings, thrust washers, bushings, seal rings, slide blocks and other wear applications. SP-21 has the highest mechanical properties of the graphite filled grades.

Vespel ® SP-22
Vespel ® SP-22 has 40% graphite by weight for enhanced wear resistance, lower friction, improved dimensional stability (low coefficient of thermal expansion), and stability against oxidation. Typical uses are the same as those for SP-21.

Vespel ® SP-211
Vespel ® SP-211 has 10% PTFE and 15% graphite by weight added to the base resin for the lowest coefficient of friction over a wide range of operating conditions. It also has excellent wear resistance up to 300°F (149°C). Typical applications include sliding or linear bearings as well as many wear and friction uses listed above.

Vespel ® SP-3
Vespel ® SP-3 is 15% moly-filled (molybdenum disulfide solid lubricant) for wear and friction resistance in vacuum and other moisture-free environments where graphite actually becomes abrasive. Typical applications include seals, bushings, bearings, gears, and other wear surfaces in outer space, ultra-high vacuum or dry gas applications.

Peek

PEEK
PEEK® was one of the first high performance commodity products available. With its combination of outstanding chemical resistance, high operating temperatures, easy machine-ability, and tremendous dimensional stability it has benefited engineers and designers. PEEK® has replaced stainless steel in numerous applications, and has proven a reliable replacement for other materials that have cost up to 10 times more. This is a versatile high performance plastic.

Torlon 5530

TORLON 5530
Torlon ® 5530 is 30% glass reinforced, compression molded PAI. It is ideal for higher load structural or electronic applications. This grade is similar in composition to Torlon ® 5030 PAI (injection molded). It is selected for larger shapes or when the greatest degree of dimensional control is required. Applications include burn-in sockets, gears, valve plates, impellers, rotors, terminal strips, and insulators.

Torlon 4203

TORLON 4203
Torlon ® 4203 extruded PAI offers excellent compressive strength and the highest elongation of the Torlon ® grades. It also provides electrical insulation and exceptional impact strength. This grade is commonly used for electrical connectors and insulators due to its high dielectric strength.

Torlon 4301

TORLON 4301
Torlon 4301 exhibits excellent wear resistance in bearing grades and is able to endure harsh thermal, chemical and stress conditions. Due to its versatile performance capabilities and proven use in a broad range of applications, Torlon 4301® is a reliable choice.

In extruded form Torlon is the highest performing melt processable plastic. It has superior resistance to elevated temperatures and is capable of performing under severe stress conditions at continuous temperatures to 500°F (260°C).

Parts machined from torlon® stock shapes provide greater compressive strength and higher impact resistance than most advanced engineering plastics. Torlon PAI's® extremely low coefficient of linear thermal expansion and high creep resistance deliver excellent dimensional stability over its entire use range.

Some key attributes of Torlon 4301® :

Excellent compressive strength
Exceptional impact strength
Maintains strength with stiffness to (260°C)
High PV rating
Outstanding electrical properties