Band saw blades
Selecting band saw blades for meat and seafood. Having the correct blade specification for a specific cutting operation likewise requires the ideal band saw machine.
Saws for cutting meat are typically of all stainless steel construction with easy to clean features. The blades either have fine teeth with heat-treated tips, or have plain or scalloped knife edges.
To have high yield in cutting a specific food product, a good band saw machine with the correct blade specification is needed. Kerf size largely determines product waste in cutting. Kerf is the total of the blade thickness (blade’s gauge) plus the tooth set. The gauge is the blade’s thickness prior to tooth setting (blade’s rear end thickness). For example, a band saw blade with a 0.5 mm (.020”) gauge may have a 0.8 mm (.032”) Kerf.
Most commercial model band saws use a 16 mm (5/8″) wide blade with thickness of 0.5 mm (.020″) or 0.56 mm (.022″), and with 3 TP1 (Teeth Per Inch) for a high-speed saw. That is, at blade speed of 900+ metres per minute (3 000 feet per minute) or faster; and 4 TPI for regular blade speed.
A band saw with a small diameter wheel (250 mm or 10”, or less) needs a thinner blade like a 0.5 mm (.020”). It makes a sharper turn for the blade in the rotation path, which shortens the life of a thicker blade.
The blade’s length depends on the diameter of the wheels and its centre-line distance from each other. This length is defined by the band saw manufacturer, including its tolerance (the blade’s minimum and maximum length accepted).
Product waste accumulates in the gullet (the space between the teeth) during cutting. The 3 TPI’s larger gullet is then better than 4 TPI on high-speed saws. Most of the waste not “caught” by the gullet remains as “dust” on the cut product. Using a 4 TPI in a high-speed band saw will most likely leave more “dust”.
Hard tooth (heat treated) on a band saw blade increases the tooth’s sharpness life and allows cutting of harder products. The tooth set is needed to cut hard products such as bones, frozen foods, etc. The so-called scallop blade (“knife blade”), usually with 2 TPI, is for slicing fresh and boneless product, in which case no tooth set is needed.
A fine set, say, 1.2 mm (.005”) gives higher yield, but the operator will exert more effort in pushing the food against the blade during cutting. A coarse set, say, 2.35 mm (.009”) will require less effort, but, of course, will have more product waste. It is then easy to understand why the blade with a coarse set gives some band saw operators the impression this blade type is sharper.
The additional cutting effort will be reduced substantially if a high speed band saw is utilised on a fine set blade. Higher labour productivity is then attained with higher product yield.
Although having a relatively shorter life, blades with thin gauge, such as 0.35 mm (.014”), with fine tooth set are best for having the best yield in costly meat products such as frozen non-shell sea foods, especially in portion cutting.
Thin blades move sideways wider, producing more product waste and, as they wobble at slow speed, have an accelerated shorter life. Therefore, thin gauge blades should be used only on a high-speed band saw with the correct narrow blade guides.
In addition to what has been stated, perhaps the most important feature of the band saw is to have a blade rotation with less lateral blade movement, even at the desired high blade speed. Band saw features that manage this specific benefit are: well-balanced wheels, wheel alignment, blade tension and blade tracking system – a feature which usually makes a band saw’s performance above the ordinary.