February, 2024- Metalworking professionals are familiar with Cosen Saws International Inc.’s line of horizontal band saws, including the scissor-style, dual-column and mitering series, as well as its vertical band saws, says Yu-Hsien Ho, director of channel sales and marketing for the Charlotte, North Carolina, machine tool builder. “Typically, we manufacture horizontal saws and stock about 40 different horizontal band saw models.”
He adds that Cosen decided to expand into different channels, such as welding and fabrication, and determined that some of those shops are small, have a modest budget or have a restrictive amount of floor space and are better suited to operate a circular cold, or cutoff, saw. “This is the type of saw for them, especially if they’re cutting tubing, pipe or extrusions and the occasional solid bar stock.”
As a result, Cosen introduced the SC-275 and SC-350 circular cold saws at last year’s Fabtech trade show. The SC-275 uses a 10- to 11-in. diameter blade and has a capacity of 2.75 in. The SC-350 uses a 14-in. diameter blade and has a capacity of 4.331 in. “When we did our market research, we found that these were two of the more common sizes,” Ho says, noting that a different style of saw is generally needed for cutting a capacity beyond what the SC-350 handles.
UPKEEP
MAINTENANCE CHECKLIST FOR CIRCULAR COLD SAWS
Keeping a circular cold saw clean, such as wiping away coolant residue daily, is critical to achieving long machine life. Cosen Saws also recommends some additional maintenance tasks.
• Change the oil every 90 days.
• Lubricate the saw head joints at grease nipple points regularly.
• Adjust the backlash until the blade can be rotated without any chatter. Over a period of use, the gears inside the saw head may become slightly worn, resulting in a clearance between gears.
• Check the air circuit.
• Apply coolant while cutting to relieve stress on the blade by reducing friction between the blade and material. Failure to use proper lubrication will result in the creation of additional heat and friction, causing the blade to dull quickly.
• Clean the flange and spindle when replacing the blade. Otherwise, chips in the flange or spindle left from previous cuts could cause the blade to wobble and shorten tool life.
IMPROVED HANDLING
The main benefit of a cold saw, according to Ho, is ease of material handling, where the workpiece is slid into the machine from the front, the operator presses on the foot pedal and the saw makes the cut. The cold saws come standard with a stop bar.
“If you’re cutting the same lengths over and over again, just set up the material stop, slide the material forward, step on the foot pedal and watch it go.”
In contrast, Ho explains, an operator must load material from the back of the band saw, come to the controls and feed the material forward. “When cutting tubing or channel on the cold saw, it is much quicker to be able to slide the material to the stopper and start the cut all within a few feet.”
The cutoff saws also feature a self-centering pneumatic vise system to clamp the material hands free. “The vise grip is V-shaped, so it will always center the material,” he says. “The operator doesn’t need to get close to the material or try to clamp it manually.”
Cosen reports that air-powered clamping operates more quickly than a hydraulically operated vise, boosting productivity. In addition, pneumatic systems tend to cost less, are more compact and weigh less than hydraulic ones.
Instead of activating a manual cold saw by pushing a button on a handle on top of the machine, the foot pedal of the Cosen semi-automatic cold saws enables an operator to stand further away from the machine when sawing, Ho says. “It’s a much easier and simpler operation.”
He adds that Cosen didn’t want to launch strictly manual models and went straight to semiautomatic for ease of use, even though end users have the option of manual operation.
A semi-automatic cold saw increases blade life by 30 percent compared to a manual clamping machine by eliminating needless blade wear due to improper use. In addition, manual clamping is more prone to operator error.
The circular cold saws have a direct-drive blade motor setup. Compared to pulley driven, a direct drive creates a higher level of torque to run the circular blade, Ho says.
STEELY SPEEDS
The cold saw motor setup allows an operator to cut at two blade speeds, depending on the application. The SC-275 offers blade speeds of 60 or 120 rpm, and the SC-350 has speeds of 26 or 52 rpm.
Cosen’s semi-automatic circular cold saws cut tubing, pipe, extrusion and solid bar stock.
The cold saws with their relatively low speeds are designed for cutting steel, including stainless steel, Ho adds. “These speeds are not optimal for cutting aluminum or brass, which typically require a much higher speed.”
When sawing high volumes of stainless solids or tubes, Ho suggests using a carbide- tipped blade, whereas a bimetal blade is suitable for sawing carbon steel unless the customer has a special application. Highspeed steel blades are also available to cut hard materials at high speeds.
In addition to the type of circular blade material, the quantity of teeth on the blade plays a critical role. Typically, more teeth should be on the blade when cutting thin-walled material, while fewer teeth are needed for solids, Cosen reports. For example, if someone is cutting 2-in. round solid carbon steel on the SC-350, the blade should have about 110 teeth. The recommended tooth count is 200 when sawing a 2-in. diameter round tube with a 0.125-in.-thick wall. The rule of thumb is to use a fine-toothed blade for thin-walled material and a coarser tooth blade for solid or thick-walled material.
“We partner with a company to provide blades for these saws,” Ho says, adding that each cold saw comes with a blade that fits the customer’s application.
To add automation to a Cosen circular cold saw, the company partnered with TigerStop to offer its push-feed system that automatically feeds material through to complete the cuts, Ho notes.
He adds that Cosen might introduce additional models in the future to saw at higher speeds or with capabilities to automatically feed material Of the SC-275 and SC-350 models, Ho says these are utility saws. “You plug in the power, air and it’s ready to go right out of the box.”
Cosen Saws International Inc., 704/943-1030, cosensaws.com
