School of Engineering · Playlist

Sawing and Bench Work

Cutoff sawing, saw blade selection, vertical band machining, and bench work.

  1. Cutoff Sawing
  2. Saw Blade Selection
  3. Vertical Band Machining
  4. Bench Work with Hand Tools
Machining/Sawing and Grinding

Cutoff Sawing

Choose a saw for the blank, hold the material securely, and leave enough material for the next operation.

Saw a blank with room for finishing

Saw a blank with room for finishing

Sawing often turns a long bar or a large plate into a manageable blank: the starting piece for machining. Plan both the material left for finishing and the kerf, the slot removed by the saw. Kerf is material lost between pieces; it is not finishing allowance.

Choose allowance from the required finished dimensions, cut quality, and later operations. A saw cut is not automatically a finished datum surface. Check dimensions and squareness before using it to locate the next cut. See Choosing Shop Measuring Tools and Shop Layout and Angle Measurement.

Match the saw's motion to the cut

Match the saw's motion to the cut

SawHow it removes materialTypical use
Power hacksawA straight blade moves back and forth, cutting on one stroke and relieving on the other. Cutting-stroke direction depends on the machine.Occasional straight cutoff work; the return stroke does no cutting.
Horizontal bandsawA continuous toothed loop advances through material clamped in a vise.Bar, tube, and structural sections cut to length. Miter capability depends on the head or vise design.
Vertical bandsawThe band passes through a table while the work is fed along a path.Straight cuts and curved outlines in plate; see Vertical Band Machining.
Cold circular sawA toothed circular blade shears chips.Repeatable cutoffs where squareness and surface finish matter. Inspect for burrs even when the cut looks clean.
Abrasive cutoff sawA thin abrasive wheel grinds through the section.Cutoff work suited to the wheel's material rating, including some hardened materials. Heat and cut quality can require further finishing.

“Cold” distinguishes chip cutting from abrasive or friction cutting; it does not mean zero heat. Use Saw Blade Selection for toothed blades. An abrasive wheel has its own selection rules.

Hold every piece, including pieces in a bundle; Checklist

Hold every piece, including pieces in a bundle

NEVER hand-hold material for a horizontal saw cut. Use the machine's vise or a suitable fixture. Support long material at the saw's working height so it does not tilt the clamped piece. Arrange support for the cutoff without trapping the blade as the cut closes.

Nesting means arranging several pieces for one cut. Clamping the outside of a bundle does not prove that its inner pieces are held. Use a nesting arrangement and clamping system approved for the machine, and select the blade for the resulting section.

  • Identify the material, section shape, finished size, and finishing allowance.
  • Confirm that the vise or fixture grips each piece and that long stock is supported.
  • Account for the kerf when locating the cut or setting a length stop.
  • Plan how the cutoff will be supported as the blade breaks through.
  • After cutting, inspect the blank and remove the burr before the next setup.

At break-through, the last connection between blank and stock disappears. Cutting resistance changes, and a thin lip of displaced metal may remain at the edge: a burr. See Bench Work with Hand Tools for deburring, and Machine Hazards and Housekeeping, Personal Protective Equipment, and Metal Chips and Swarf for hazards and precautions.

Choose speed, feed, and coolant together

Choose speed, feed, and coolant together

Band speed is the distance the blade travels per minute, usually stated in feet/min or m/min. Feed is the rate or force that advances the blade into the work. They are different adjustments. Material grade and hardness, blade material, tooth geometry, and section shape all affect the starting settings.

Use the blade maker's cutting chart for the actual material, then follow the machine manual for setting it. Follow the blade maker's break-in procedure for a new blade. There is no single speed table or fixed percentage adjustment that fits every saw. Connect these terms to Feeds and Speeds.

On a saw designed to use cutting fluid, the fluid helps lubricate the cut, carry away heat, and clear chips. Use the approved fluid, concentration, and delivery method. Some abrasive cutoff systems are dry and others are wet; do not add coolant to a dry-only setup.

Supporting detail: Addendum 1 — Why finer teeth do not fix every bad cut.

Machining/Sawing and Grinding

Saw Blade Selection

Use section shape, teeth in the cut, tooth form, set, and blade material to narrow the choice before consulting the maker's chart.

Pitch spaces the teeth; gullets carry the chips

Pitch spaces the teeth; gullets carry the chips

TPI means teeth per inch along the blade. A higher TPI is a finer pitch. For evenly spaced teeth, pitch in inches is 1 ÷ TPI. The gullet is the hollow between teeth that provides chip space. Set is the sideways displacement of teeth, making clearance for the blade body in the kerf.

Side view shows pitch between adjacent tooth tips and the gullet between teeth; an edge view shows teeth set to either side of the blade body.
Pitch is measured along the blade. Set is seen from a different direction. Shapes are schematic.
Estimate teeth in the cut before choosing TPI; Interactive; Practice

Estimate teeth in the cut before choosing TPI

As a rule of thumb, aim to keep at least about three teeth engaged. For a uniform pitch crossing one continuous thickness of material:

Estimated teeth engaged = contact length in inches × TPI
Minimum TPI for three teeth = 3 ÷ contact length in inches

Use thickness measured along the tooth line through solid material, not automatically the height of the part. For 0.25 in of continuous contact at 12 TPI, the estimate is 0.25 × 12 = 3 teeth. At the same thickness, the three-tooth calculation gives 3 ÷ 0.25 = 12 TPI.

At the same 8 TPI, a 0.25 inch contact length spans about two teeth and a 0.75 inch contact length spans about six teeth.
Same tooth spacing, different contact length. The thinner section needs a finer pitch to meet the three-tooth estimate.

A calculated minimum is a screening value, not a blade specification. If it falls between available pitches, select a suitable finer option from the maker's chart rather than rounding down. Excessively fine teeth can run out of chip space in thick stock.

Supporting detail: Addendum 2 — Why the answer can be a fraction of a tooth.

Predict first: at mid-depth in the thin-wall tube below, would doubling TPI halve, double, or leave the estimated engagement unchanged? It doubles: the same contact length contains twice as many tooth spacings.

Dashed line = about three teeth; shading = below three. Each plot uses its own vertical scale.

Thin-wall tube, coarse blade

Teeth · top of scale 4.000050.80Cut depth (mm)

50.80 mm outside diameter; 1.00 mm wall; 6 TPI.

At depth 25.40 mm: 0.47 teeth across 2.00 mm of material.
Across the cut: minimum 0.00; maximum 3.33 teeth.

Below the common rule of thumb of about three teeth.

Contact tends to zero at entry and exit. At mid-depth only the two walls count. The peaks occur where the blade touches the inside circle.

Thick solid bar, fine blade

Teeth · top of scale 55.200025.40Cut depth (mm)

50.80 mm contact thickness; 25.40 mm feed height; 24 TPI.

At depth 12.70 mm: 48.00 teeth across 50.80 mm of material.
Across the cut: minimum 48.00; maximum 48.00 teeth.

At or above about three teeth here; this is not a blade approval.

Gullets may fill with chips; check the blade maker's guidance.

Estimated teeth = solid contact length ÷ tooth spacing; mm per tooth = 25.4 ÷ TPI. Readouts round to two decimal places; calculations keep the unrounded, real-valued estimate. Highlighted tooth tips illustrate one blade position, not a guaranteed integer count.

Round-section minima include the exact entry and exit tangencies, where contact is zero. A flat bar has constant contact through its feed height, including the limiting faces. Rotate the flat bar 90° to swap contact thickness and feed height; rotating a round bar or round tube about its axis changes neither. This model is a straight tooth line crossing an ideal section, with uniform pitch and no blade tilt.

The thick-bar, fine-blade preset highlights the full contact region as a reminder: gullets may fill with chips; check the blade maker's guidance. It sets no numeric upper limit. Tooth count alone cannot predict chip filling. For shop practice and hazards, see Cutoff Sawing and Safety collection.

Practice teeth in the cut Practice minimum TPI

A tube's outside diameter is not its solid thickness; Practice

A tube's outside diameter is not its solid thickness

A solid bar offers continuous material across the blade's path. A tube, angle, or channel presents walls and gaps, and the contact changes as the cut progresses. Select from a chart for tubes or structural sections, using wall thickness, overall dimensions, and orientation as that chart requires.

Thin walls generally need finer teeth than a solid bar of the same outside size. Do not multiply tube outside diameter by TPI and count the empty center as cutting engagement. Nor does simply adding two wall thicknesses describe every stage of a round tube cut.

Variable pitch alternates tooth spacing within a repeating group. It can reduce repeated tooth-impact vibration and suit changing engagement, but it still needs to match the material and section.

Practice tube versus solid selection

Tooth form and set describe different features

Tooth form and set describe different features

Tooth formSelection idea
Regular or standardCommon general-purpose form, typically with a zero rake face. Fine versions suit thinner sections.
SkipWidely spaced teeth with generous gullets, typically zero rake; useful when softer materials and larger chips need clearance.
HookA positive rake face takes a more aggressive bite. Use where the maker recommends it for the material and the machine can support the cut.

Rake describes the angle of the tooth face that meets the material. Exact angles vary by blade; “hook” does not specify one universal angle.

Set patternArrangement and use
RakerA common sequence is left, right, straight. A general-purpose arrangement; the straight tooth is unset.
AlternateSuccessive teeth are set left and right.
WavyGroups of teeth vary their sideways set in a wave. Common on fine-pitch blades for thin sections.

Set pattern does not replace pitch selection. Choose the complete blade specification, not a tooth-form name alone.

Choose blade material and dimensions for the machine

Choose blade material and dimensions for the machine

  • Carbon steel: an economical choice for suitable easy-to-machine materials and lighter service.
  • Bimetal: high-speed-steel cutting teeth joined to a flexible alloy-steel back; widely used for metal cutoff work.
  • Carbide-tipped: carbide cutting tips for applications needing greater wear resistance, with a compatible machine and cutting conditions.

Match blade length and thickness to the machine. Blade width, measured from tooth tip to back, also affects contouring; see Vertical Band Machining. Material name alone does not establish a blade's hardness limit or speed. Use the maker's product chart for the actual alloy and condition.

Supporting detail: Addendum 3 — Manufacturer resources for the next selection step.

Machining/Sawing and Grinding

Vertical Band Machining

Plan contour cuts around blade width and turning radius, and recognize the purpose of blade welding, band filing, and polishing attachments.

A vertical band follows a contour through the work

A vertical band follows a contour through the work

A vertical bandsaw supports the work on a table while a continuous band cuts through it. Moving the work along a marked path allows curved outlines as well as straight cuts. This can remove excess material before milling a profile.

Leave the planned finishing allowance on the retained side of the line, including room for the kerf. Use Shop Layout and Angle Measurement for marking the path and Choosing Shop Measuring Tools for checking the result. Tooth pitch and blade material are covered in Saw Blade Selection; speed and coolant in Cutoff Sawing.

The tightest curve sets the blade-width limit

The tightest curve sets the blade-width limit

A narrow blade can turn a tighter curve; a wide blade better resists wandering in a straight cut. Find the smallest radius on the intended saw path, then use the blade maker's width-versus-minimum-radius chart. Choose a width that fits both that path and the machine.

Radius is measured from the center of a curve to its edge; diameter is twice the radius. A chart's minimum radius is not a guarantee for every blade with that width: blade thickness and kerf clearance matter too. Do not force a wide blade around a tighter corner than its chart permits.

Supporting detail: Addendum 4 — Why relief cuts help with some outlines.

Blade welding closes the loop for some internal cuts

Blade welding closes the loop for some internal cuts

Blades may arrive as ready-welded loops. On equipment designed for it, a suitable open band can pass through a starting hole in the work and then be joined, making an internal contour accessible without a slot from the outside edge.

In general, blade joining involves preparing and aligning the ends, making a butt weld, heat-treating the joint as specified, finishing the weld flush, and inspecting it. The joint must flex around the wheels and pass through the guides. Follow the welder and blade maker's instructions for the exact sequence and settings; not every blade construction is suitable for a shop blade welder.

Supporting detail: Addendum 5 — Why joining includes more than making a weld.

Filing and polishing require their own bands and guides

Filing and polishing require their own bands and guides

Some band machines accept a file band to remove small amounts of material and refine a contour, or an abrasive band to smooth a surface. These are dedicated attachments with matching guides and operating instructions, not ordinary saw blades used differently.

Confirm that the machine supports the attachment before selecting its band, speed, or lubricant. Hand finishing methods are in Bench Work with Hand Tools. For operating hazards and precautions, use Machine Hazards and Housekeeping, Personal Protective Equipment, and Metal Chips and Swarf.

Machining/Sawing and Grinding

Bench Work with Hand Tools

Hold a part in a bench vise, saw by hand, choose and clean files, and remove burrs without losing the intended shape.

Use the vise to make the part steady

Use the vise to make the part steady

A bench vise holds the part while both hands control the tool. Clamp near the working area with enough material between the jaws to resist movement. Excessive projection makes the part flex and chatter. Use suitable soft jaw covers when the ordinary jaws would mark a finished surface, and support long pieces.

Keep the cut or filing area accessible. A thin-walled part may need shaped support so clamping does not distort it. Check dimensions with Choosing Shop Measuring Tools and place lines using Shop Layout and Angle Measurement. For hazards and precautions, see Machine Hazards and Housekeeping, Personal Protective Equipment, and Metal Chips and Swarf.

A conventional hand hacksaw cuts on the push stroke; Practice

A conventional hand hacksaw cuts on the push stroke

Install the blade with its teeth pointing away from the handle for the conventional push-cut setup, and tension it according to the frame's instructions. Choose pitch for the material actually crossed by the teeth: thin sections need finer teeth. Apply the three-teeth rule of thumb from Saw Blade Selection.

Start a shallow groove with controlled strokes. Once established, use long, even strokes that spread the work over the blade. Apply cutting pressure on the forward stroke and ease it on the return. Keep the blade aligned with the cut instead of twisting it to steer back to the line. Ease pressure as the cut nears completion and plan support for the separated piece.

Practice blade direction

File cut and coarseness are separate choices; Practice

File cut and coarseness are separate choices

A file removes small chips with many teeth. Choose its shape to reach the surface: flat for a flat face, round for a round opening, or half-round for both flat and curved areas. A safe edge has no cutting teeth, allowing work close to an adjoining surface that should remain uncut.

Single-cut file face has one family of diagonal teeth; double-cut face has two intersecting families.
Cut pattern is not a coarseness grade. The drawing enlarges the tooth spacing for comparison.

Single-cut files have one family of parallel tooth cuts; they are useful for controlled finishing and draw filing. Double-cut files have crossing cuts that divide the teeth into smaller cutting points; they commonly suit faster stock removal.

Coarseness describes tooth spacing. Common grades run from rough, coarse, bastard, second-cut, smooth, to dead smooth, from coarser to finer. Availability varies. Compare grades within the same file family and length; the name alone is not a universal tooth-spacing measurement. “Second-cut” is a coarseness grade, not another name for double-cut.

Practice file choice

Keep the file flat and its teeth clear

Keep the file flat and its teeth clear

Fit a suitable handle to a tanged file. For ordinary forward filing, guide the file with both hands, keep it level, apply pressure on the cutting stroke, and ease pressure on the return. Rocking rounds the edges of a surface intended to stay flat. Check progress frequently rather than filing past size.

For draw filing, hold a suitable single-cut file crosswise to the work and move it along the surface, with its length across the direction of travel. Use light, controlled pressure and orient it so the teeth cut on the working stroke. This helps blend marks and refine a flat surface.

Chips lodged in the teeth are called pinning; they can scratch the work. Clean with a file card, brushing with the tooth grooves to clear trapped chips. Store files so their teeth do not rub against other tools.

Supporting detail: Addendum 6 — File selection and care resources.

Remove the burr without changing the required edge

Remove the burr without changing the required edge

Deburring removes the thin unwanted lip left by cutting. Use a file for accessible straight edges, a suitable swivel-blade deburring tool for edges it can follow, or a suitable countersinking tool for a hole entrance. Match the cutter to the material and edge shape.

Take light passes and inspect the result. Removing a burr does not authorize a large chamfer or a rounded edge. Preserve the drawing's dimensions and edge requirements; if an edge break is specified, make that feature deliberately.

Scribers mark; hammers and punches move or indent material

Scribers mark; hammers and punches move or indent material

A scriber makes a fine line with a hard point. Use it for the marking method described in Shop Layout and Angle Measurement, rather than as a substitute for a punch.

A ball-peen hammer supplies controlled blows for appropriate metalworking tasks. A soft-face hammer can reduce surface marking when positioning a part; it does not guarantee that a delicate surface will be unmarked.

A center punch makes an indentation for locating a drill start. A pin punch drives a pin with a flat-ended tip sized for that pin. Choose the tool for the task: the pointed center punch is not a pin driver. Detailed measuring and layout procedures belong in Shop Layout and Angle Measurement.

Supporting detail

Addendum

Additional evidence, standards context, and background referenced from the main text.

  1. Machining/Sawing and Grinding/Cutoff Sawing

    Addendum 1. Why finer teeth do not fix every bad cut

    More teeth share the load, but smaller gullets have less room for chips. Too much feed can overload the teeth; too little can make them rub. A wandering cut also calls for checking the blade condition, tension, guides, and workholding against the manuals. Changing speed alone cannot correct loose work or a worn guide.

    Back to reference 1

  2. Machining/Sawing and Grinding/Saw Blade Selection

    Addendum 2. Why the answer can be a fraction of a tooth

    The product counts tooth spacings across the contact length. Actual engaged tooth tips are discrete, and the number changes as the blade moves. Entry, exit, variable pitch, and curved sections also change contact. This estimate explains the selection principle; it does not guarantee a fixed count throughout a real cut.

    Back to reference 2

  4. Machining/Sawing and Grinding/Vertical Band Machining

    Addendum 4. Why relief cuts help with some outlines

    A relief cut runs in from a scrap edge toward the outline, allowing waste to separate in smaller pieces. Plan relief cuts on the waste side and preserve the finishing allowance. They can provide room to approach a contour from another direction; they do not make the blade itself capable of a smaller turning radius.

    Back to reference 4

  5. Machining/Sawing and Grinding/Vertical Band Machining

    Addendum 5. Why joining includes more than making a weld

    Alignment keeps the band running straight. The prescribed annealing or tempering cycle restores suitable flexibility at the joint, and finishing removes raised weld material. A sound-looking joint alone is not proof that the loop is ready to run. DoALL's blade welder range is a starting point for equipment-specific documentation.

    Back to reference 5