HIGH CARBON CAST

STEEL SHOT AND GRIT

PRODUCT

High Carbon Cast Steel Shot & Grit are durable metal abrasives. Typical sieve analyses of these products are given in the following tables and gradation charts. Atmospherically controlled heat treatment and quench provide uniform microstructure and harness ranges for optimum durability.  Shot and Grit Abrasives are most frequently provided in a standard range of 40-51 Rockwell C. 

USES AND ADVANTAGES

	Impact cleaning and de-scaling of ferrous or non-ferrous castings, forgings, steel mill products, weldments and heat treated metal products.
	Shot peening to impart residual stresses, improving the fatigue properties of metal products.
	Inspection of billet surfaces.
	Rail cars, containers. Surface preparation for coating.
	Ship building, structural steel fabrication, pipe and rebar. Surface preparation for coating.
	Floor and deck restoration.
	Surface preparation of fiberglass and other products.
	Roll etching for steel mills, paper mills and other profile preparation.
	Granite and marble cutting.
	Bridge painting and restoration.
	Core drilling.
	Ballast and counterweights.

STANDARD PACKAGING

Palletized 55 gallon, non-returnable drums

Shot Packaging

      All sizes 2000 lbs net

Grit Packaging

      G10 – G16      1800 lbs net

      G18 – G40      1700 lbs net

      G50                  1600 lbs net

      G80 – G120      1500 lbs net

OPTIONAL PACKAGING

	Palletized carton containing 40 – 50 lb multi-wall paper bags.
	Bulk Bags packaged 4000 lbs net.

CHEMICAL ANALYSIS

Carbon                                          0.80 – 1.20%

Manganese

            HCS S70 – HCS S110   0.35 – 1.20%

            HCS S170                        0.50 – 1.20%

            HCS S230 and up           0.60 – 1.20%

Silicon                                           0.40% Minimum

Sulfur                                             0.05% Maximum

Phosphorous                                0.05% Maximum

The microstructure of high carbon cast steel shot shall be uniformly tempered martensite with fine, well-distributed carbides, if any. Carbide networks, transformation products, decarburized surfaces, inclusions, porosity and quench cracks are undesirable. 

DENSITY

High carbon cast steel shot shall not weigh less than 7 gm/cc nor contain more than 10% hollows. The method of determining density may be an alcohol displacement method, but for critical density measurements, a pycnometer method is recommended.

GENERAL APPEARANCE

High carbon cast steel shot shall be as nearly spherical as is commercially possible with a minimum of elongated or compound particles, tails, hollows, broken pieces, slag and dirt. 

HARDNESS

Ninety percent of the hardness checks performed on a representative sample shall fall within the range of Rockwell C 40 to 51 HRC. (This is S hardness shot and grit.) The hardness may be determined by any of the various methods applicable to small sections such as a Tukon Tester with Vickers indenter, at loads determined to provide a reliable conversion to Rockwell C. 

STEEL FOUNDERS’ SOCIETY OF AMERICA

20-66 Standard Specification for Cast Steel Abrasives

MICROSTRUCTURE

The microstructure of the abrasive shall consist of martensite tempered to a degree consistent with the hardness range. The presence of free ferrite or free graphite is unsatisfactory.

VOIDS

No more than 10% of cast steel abrasive particles shall contain voids as determined at 10X magnification. A void must be greater than 10% of the area of the abrasive to be considered harmful.

SHRINKAGE

No more than 10% of cast steel abrasive particles shall contain shrinkage as determined at 10X magnification. A shrinkage area must be greater than 40% of the area of the abrasive particle to be considered harmful.

CRACKS

No more than 15% of cast steel shop particles, and no more than 40% of cast grit particles, shall have cracks as determined at 10X magnification. A crack is a linear discontinuity whose length is greater than 3 time its width and greater than 20% of the diameter or shortest dimension of the abrasive particle.

PARTICLE SHAPE OF SHOT

When examined at 4X magnification, no more than 5% of the shot particles will have a length that is in excess of twice the cross section.

STEEL SHOT

Screen Opening Sizes and Screen Numbers with Max and Min Cumulative Percentages Allowed on Corresponding Screens