Abrasive shots are shots used for cleaning, smoothening, peening, stripping, shaping and improving a metal surface in the blasting and shot peening machines. There are various types of abrasive media available which may be broadly categorized into three main streams as:
- Glass beads
There are various types of shots such as steel shots, SS shots, cut wire shots, steel cut wire shots, zinc cut wire shots, Aluminum Cut Wire Shot, Copper Cut Wire Shots, Brass Cut Wire Shots, etc.
Steel shot is manufacturing by scrap of metals in electric furnace. This Molten metal is controlled by spectrometer. Spherical or circular balls are made of molten steel through an atomization process. This is quenched and tempered in a heat treating process to obtain a product of uniform hardness and microstructure, screened by size and specification.
These are available in different sizes and hardness by this process. These are used in surface preparation process for cleaning metal surfaces which are covered with mill scale, dirt, rust, corrosion or paint coatings and for physically modifying the metal surface such as creating roughness for better application of paint and coating, peening and for smoothening of any material. Mostly industries are using steel shots are automotive, body shop, metals, Military/ Defense, Shipyards/ Dockyards, aviation industries etc
Stainless Steel Shots are the shots made from stainless steels. Used for cleaning, peening and smoothening of surface. These are costlier as compared with steel shots. Application used where we need no rust because some metal or material react with the shots and thus material gets destroyed due to rust on them which further cannot be used; thus to avoid 100% rust we use SS shots.
Cut wire shots:
Cut Wire Shot is cylindrical in shape. Cut Wire Shot is made from high quality wire which is cut to a length about equal to its diameter. The wire used to produce Cut Wire Shot can be made of Carbon Steel, Stainless Steel, Aluminum, Zinc, Nickel Alloy, Copper or other metal alloys and even thus named after that such as zinc cut wire shots, copper cut wire shots, aluminum cut wire shots, etc. Used in Shot Peening, blast cleaning and vibratory finishing. Cut wire shots size is calculated in mesh or mm.
GRITS There are various types of grits such as steel grit, Aluminum Oxide Grit, Cast Iron Grit, Chilled Iron Grit, etc.
Steel grit is grains / circular steel balls with a predominantly angular shape. These are obtained by crushing steel shot; therefore they exhibit sharp edges and broken sections. These are harder in nature than steel shot; it is also available in different sizes and hardness. Used in removing rust, corrosion, removal of paints from cars, etc. Industrial application of steel grit is cleaning, surface preparation, Shot peening, stone cutting, etc.
Aluminum Oxide grit:
Aluminum Oxide Grit is a sharp edges type, long lasting abrasive material that is highly efficient and reusable. It is harder than most blast media, Aluminum Oxide Blast Media, will clean and etch quickly on all type of surfaces. Aluminum oxide can be recycled many times. It is the most widely used abrasive grain in sand blast finishing and surface preparation because of its low cost, longevity, and hardness. Aluminum oxide grit powder penetrates and cuts even the hardest metals. It is categorized in three colors according to their use such as white, black and brown. Brown aluminum oxide contains less than 1.5% free silica and is safer to use than sand. The grit size is consistent and cuts much faster than sand, leaving a smoother surface, finished properly. The larger the grit size, the faster aluminum oxide will cut. Its high compressive strength, high hardness, resistant to abrasion, high thermal conductivity & high dielectric strength.
Chilled Iron grits:
Chilled iron grit is a dense, brittle, hard abrasive media making it suitable for etching purposes, but less resistant to impact. In the blasting process chilled iron breaks at an angle producing a mixture of sharp grit to roughen up the hardest surface and clean quickly. It should be used in blast rooms for fast cleaning and edging but shouldn’t be used in wheel blast machines, since it quickly wears down the machines parts. Chilled iron grit is especially suited for air blast applications requiring an aggressive cutting rate, and angular profile. Applications of chilled iron grit are cleaning of steel fabrications such as trailers, ships, bridges. Advantages of chilled iron grit are rapid cleaning rate, hard in nature, low lifetime cost as it breaks down slowly and can be used many times.
Glass Beads are an environmental-friendly and clean abrasive media that is aggressive enough to clean and deburr parts, do not damage them. Glass beads can be recycled up to eight times or more. Abrasive blast cabinets provide the best recyclability rate. Bead blasting is very dangerous. It is dangerous as we can be pelted by hot glass as well as inhale paint and rust during the process. This means we need to protect ourselves. Glass beads can cause severe skin problems. Glass Beads will clean metal parts without etching the blasting surface. Glass Beads are commonly used for automotive restoration, polishing of castings,stainless steel fabrication, and light deburring of small parts. Glass Beads are most commonly used in abrasive blast cabinets. Its round shape cleans metal parts, leaving a smooth, polished or matte finish. Glass bead having many grades which is known by AB, AD, AC, AF, C It has low dust levels. These low dust levels improve the operator’s visibility of the work surface, even increasing production rates. It also reduces cleanup costs on the work site.
Application of abrasive shots: Glass Beads can perform a wide range of abrasive blasting jobs. Larger sizes glass beads can be used for the cleaning of automotive parts, castings, mould cleaning of footwear, tyre moulds and various types of rubber industries mould cleaning, it is also used in deburring rough edges from castings and gears. Medium sizes glass beads are suited for blending surface, defects and working with aluminum and stainless steel parts, providing a satin to matte finish. Fine sizes of glass beads work best for light duty work and allow for fine detail work in engraving stone or wood.