Saws

Chain saws, 1910.266(e)

A chain saw is a powerful tool that can be used for a variety of purposes, such as cutting firewood and clearing land. Some of the hazards associated with chain saw use are: kickback, burns, electrocution and loss of control.

Many chain saw accidents are caused by kickback. Kickback is the reactive force that happens when the nose or tip of the guide bar comes in contact with a solid object or is pinched and recoils toward the operator. Saws manufactured since 1985 come equipped with at least three anti-kickback features. Reactive forces can cause loss of control and result in a serious injury.

Circular/crosscut/ripsaws, 1910.213, 1910.243

These table saws are used for straight sawing. Depending on the blade, they cut either across (crosscut) or with (ripsaw) the grain of the wood. With the hand-fed saws, the operator adjusts the height and angle of the blade. Then, holding the stock, the operator pushes it into the blade. A guide is used to maintain a straight cut at the desired width. At the end of the cutting stroke, the operator either changes positions or pushes the stock past the blade. Self-feed or power table saws are equipped with rollers or a conveyor system to hold the lumber and force-feed it into the saw blade.

Injuries can occur if an operator’s hands slip as he or she is feeding the stock into the saw or if the operator holds his or her hands too close to the blades while cutting. Employees can also be injured when removing scrap or finished pieces from the table. Kickbacks (that is, when the blade catches the stock and throws it back toward the operator) are another major cause of injury. Kickbacks can result if the blade height is not correct or if the blade is not properly maintained. Kickbacks are more likely to occur when ripping, rather than crosscutting. Kickbacks also can occur if safeguards are not used or if poor-quality lumber is cut.

Overhead swing and straight line pull cutoff saws, 1910.213

These are special types of circular saws, which are also used for straight cutting. They are preferred for cutting long pieces of stock. The overhead swing saw is suspended from the ceiling and is generally attached directly to the motor shaft. To run the saw the operator pulls it forward like a pendulum.

Injuries can occur if the operator reaches to remove a section of board while the blade is coasting or idling, or if the operator tries to measure a board or position it while the saw is still running. Injuries can also occur if an improperly adjusted saw swings beyond its safe limits.

Radial saws, 1910.213

Radial saws are circular saws that cut downward, either with or against the wood grain (rip or cross-cut). For crosscutting, the wood is pushed away from the operator and against a fence. For rip cuts, the blade is set parallel to the fence, and the stock is pushed through. The saw blade rotates upward toward the operator; who feeds the stock in the opposite direction of the blade movement.

Radial saws have features that make them more versatile than table saws. The saw arm can be raised and lowered and swung from side to side to adjust the depth and horizontal angle of the cut; the blade can be replaced with shaping cutters, disk or drum sanders, and other accessories.

The principal types of injury from radial saws are cuts to the arms and hands, or amputation of fingers, from contact with the blade or flying wood chips. Workers can also be injured from kickback. Employees working nearby can be seriously injured if stock that is fed in the wrong direction is flung out of the saw.

Band saws,1910.213

Band saws are used for both straight sawing and for cutting curved pieces. The band saw uses a thin, flexible, continuous steel strip with cutting teeth on one edge. The blade runs on two pulleys, driven and idler, through a hole in the work table on which stock is fed. The operator hand-feeds and manipulates the stock against the blade to saw along a predetermined line.

Although workers are not injured as frequently or as severely on band saws as on circular saws, injuries do occur. The most common injury is caused by contact with the blade. Contact with the blade at the point of operation occurs because the operator’s hands may come close to the blade during cutting, and band saws cannot be completely guarded.

Jig saws, 1910.213

Jig saws are useful for precision-cutting intricate curves and patterns on thin stock. They have thin blades that move rapidly up and down through the opening in the saw table. The blade is held in upper and lower chucks that pull it tight and keep it from bending. A hold-down adjusts to the thickness of the wood being cut.

Jig saws are generally not considered to be as dangerous as other saws; however, contact at the point of operation can cause hand and finger injuries. Contact with the blade can also occur below the table. All portions of the blade must be guarded.

Jointers, 1910.213

Jointers face or flatten wood and are primarily used to joint small pieces of material. The operator passes stock over a cylindrical, multiple-knife cutter head, while keeping the stock flush against a guide. The depth of the cut is achieved by adjusting the front table. There are two types of jointers: hand-fed jointers with a horizontal cutting head, and wood jointers with a vertical head.

Hand-fed jointers are dangerous woodworking machines. Injuries can occur if the operator’s hands and fingers come in contact with the knives. This can happen when the operator is jointing narrow lengths of stock, particularly if he or she does not use a jig or other holding device. Injuries can occur when the operator allows his or her fingers to ride along the surface of the jointer as the wood is fed through. Also, stock may be accidentally kicked away, exposing the operator’s hands to the cutter head.

Shapers, 1910.213

Shapers are most commonly used to shape the edges of stock. The operator feeds the stock from any direction against a vertical rotating cutter mounted on a spindle. The spindle rotates at a high speed. Some machines have multiple spindles. Guidepins hold the stock for curved shaping and fences hold it for straight line shaping.

Injuries can occur when the operator’s hands or fingers contact the revolving knives. Workers can also be seriously injured or killed by tool projection from unbalanced cutter heads. Shapers are difficult to guard; however, a number of guards are available to protect operators’ hands.

Power-feed planers/moulders, 1910.213

Also called surfacers, planers are used to dress and size rough-sawed lumber on one or more sides. They plane boards to an even thickness. Stock passes under or between cylindrical cutter heads with multiple knives. Planers are similar to jointers except that the cutter head is above, or above and below, the stock. The operator adjusts for the cut and then feeds stock into the in-feed side of the machine. The surface board is retrieved from the out-running end.

Automatic feeding mechanisms make this equipment less hazardous. However, operators’ hands may be pulled into the cutting area, and can come in contact with the point of operation while adjusting blades. Operators’ hands also may be pinched between the stock and in-running rolls, if the feed system is not properly guarded.

Lathes, 1910.213

Lathes are used for shaping round parts, such as table legs. Two types of lathes are used in the woodworking industry: automatic-feed and manual-feed. In an automatic-feed lathe, the stock, mounted on a carriage, is moved into contact with a multiple-knife cutter head that runs the entire length of the stock. The stock rotates at a low speed, while the cutter rotates faster. Using a feed lever, the operator feeds the stock into the cutter head and maintains the proper pressure for effective cutting.

In a hand-fed lathe, the stock, mounted between two centers, rotates rapidly while the operator applies a single-point tool to the wood. The operator holds the tool on a tool rest and advances it along the length of the tool rest to shape the stock as desired.

The primary hazards of lathes are contact with rotating parts and contact at the point of operation. Operators’ hands, clothing, or jewelry may be caught on the rotating parts and pulled into the machine. The danger is greater with hand-fed lathes, because the operator works in such close proximity to the rotating stock and the cutting tool. With automatic lathes, the operator can contact the rotating parts if he or she reaches into the work area to adjust components while the machine is running. Flying chips are also a hazard on lathes.

Sanders, 1910.213, 1910.243(a)(3)

Sanders finish stock by using a coated abrasive surface to remove material. There are three general types of sanders: drum, belt, and disc. A belt sander uses a system of pulleys to move the abrasive material across the stock. Either the wood is fed manually or automatically into the machine or the sanding belt is pressed toward the wood, which is located on a working table.

Sanders produce a considerable quantity of fine wood dust. All sanders should be carefully ventilated. The primary safety hazard of belt sanders is that workers may catch their hands, clothing, or jewelry in the in-running rolls. Also, contact with an abrasive surface can cause abrasions and lacerations.

Routers, 1910.213

Routers are used for such purposes as cutting and shaping decorative pieces, making frame and panel doors, and milling moldings. Routers have spindles that spin variously shaped, small-diameter cutting tools at high speeds. The tool is held in a collet chuck and protrudes through a flat, smooth base that slides over the surface of the work. The tool-spindle axis is usually vertical, but it may be tilted. The operator lowers the head for machining, and the head automatically returns to its original position after the cut is made. The spindle is driven by belts and pulleys or by a high-speed motor.

Operators may be injured from inadvertent contact with the rotating tool when handling the stock or removing scrap from the table. Kickback is another common source of injury among router operators. Kickback may be caused by poor-quality lumber (i.e., if the stock breaks) or incorrect work method, such as feeding the stock into the tool too abruptly or in the wrong direction, or poorly fixing the stock to the template.

Projection of tools can severely injure or kill router operators. Tools can be flung from the cutter head if they are poorly fastened in the tool holder, if the wrong tool is used, or if the tool speed is too high.

Tenoning machine, 1910.213

Tenoning machines use cutter heads and/or saw blades to form projections (tenons) on pieces of stock. Each tenon can be inserted into a cavity (mortise) on another piece of wood to form a mortise and tenon joint.

Boring/Mortising machine, 1910.213

Boring and mortising machines use boring bits or mortising chains to cut cavities in pieces of stock. These cavities are often used in mortise and tenon joints.