What to order, in the words we use at the counter.

6061 is commonly chosen for strength and machinability. The temper matters too: compare the full alloy and temper designation, not just the four-digit alloy.

6063 is common in architectural extrusions, trim and post-and-panel work. It is often chosen for surface finish and anodizing. That does not make it suitable for every visible part.

Neither alloy name is a load rating. For railings, ramps and other load-bearing parts, check the design, connections and applicable requirements with a qualified professional.

T6 is solution heat treated and artificially aged: the hardest common temper. Stiff, strong, and it will crack before it takes a tight bend.

T5 is cooled from the extrusion press and aged. A little softer and more forgiving, common on 6063 shapes.

T4 is naturally aged and softer again — the one to ask for if you plan to bend or form the piece before it goes in.

Bending T6 around a tight radius usually ends in a crack. That is the temper doing what it is meant to do, not a bad piece of metal.

Square and rectangular tube sizes describe nominal outside dimensions. Wall thickness is a separate measurement. A thicker wall leaves less room inside the same outside size.

Example, not a stock listing: a 2 in square tube with 1/8 in wall has approximately 1 3/4 in inside. The same outside size with 1/4 in wall has approximately 1 1/2 in inside. Subtract twice the wall from each outside dimension.

Those inside sizes are arithmetic, not guaranteed clearances. Extrusion tolerances and corner shapes affect the fit. Measure the actual opening before ordering a sleeve or a part that must slide inside.

At matching outside dimensions and alloy, a thicker wall generally increases bending stiffness and weight. Doubling the wall does not mean twice the strength, twice the weight or twice the price. Read the price on the tag rather than estimating it from wall thickness.

Wall alone cannot specify a railing, ramp or trailer part. Span, loads, orientation, connections, alloy and temper all matter. Use qualified design guidance for anything carrying people or a safety-critical load.

Welding, bending and tapping need their own checks. Heat changes material properties, while bends and threads need suitable geometry. A heavier wall is not a substitute for checking the whole part.

Before buying, write down outside size, wall, alloy, temper and cut length. Check each against the tag. If a fit matters, ask the counter to confirm the actual dimensions before paying.

Compare the measured tags on the tube rack. Then check what a cut costs before typing your lengths.

References: Metals Depot's square tube dimensions and Hydro's alloy guidance. Examples explain dimensions; the rack states what this shop has.

A sheet tag is one actual sheet, and it is priced by the square foot. Type the rectangles you want — width by length — and you pay for the area you asked for, plus the shear.

Thickness on sheet is written in decimals, not fractions. .080 is the skirt and panel thickness most post-and-panel work uses; .125 is an eighth of an inch and stiffens up a lot; .190 and up is plate you can machine and tap.

We turn each piece whichever way fits the sheet, so a 24 x 36 and a 36 x 24 are the same order. Nothing under 2 in on a side: the shear cannot hold it.

One sheet, one tag. When your pieces come off it, the rest of that sheet comes off the rack with it, and we re-tag the drop at its measured size. So the sheet you are looking at is whole until somebody buys from it.

The plus-or-minus sign allows the cut to be longer or shorter than the requested length. Both directions count. It does not mean extra length is guaranteed.

Example, not a stock listing: request 24 in with a tolerance of ±1/8 in. The permitted length runs from 23 7/8 in to 24 1/8 in. That is a 1/4 in range overall.

The cut-length tolerance says nothing about the tube opening, wall thickness or corner shape. It is not a promise of machined end faces or a specified end squareness. A part that must fit another part needs its own dimensional checks.

If you will machine the ends, choose the extra material with whoever will finish the part. Allow for the shortest permitted saw cut, not just the target length. Do not assume adding 1/8 in leaves 1/8 in for machining.

Write down your final dimensions and required tolerances before ordering a close-fit part. Ask the counter whether the saw cut meets those requirements. Confirm any finishing work separately before paying.

Type lengths in inches or feet, including fractions. The cut list rounds entered lengths to the nearest 1/8 in. That rounding sets the target; the cutting tolerance is a separate allowance around it.

Check the displayed length before checkout. For a safety-critical part, confirm the complete specification with a qualified professional. A saw-cut length alone does not establish suitability.

Read the current tolerance below, then open the rack to build your cut list. Check what a cut costs before ordering.

Reference: American Micro Industries explains dimensional tolerances and fit. The example explains ± notation; this shop's current tolerance appears below and on each cut list.

Pay online and the pieces are cut, tagged with your tag number, and set on the will-call shelf. Come in during shop hours and ask for it by tag number at the counter.

How fast is fast: pay on a weekday before 4p and your pieces are on the will-call shelf before 5p the same day. Pay after 4p, or on a weekend, and they are ready before 5p the next shop day. The receipt tells you which, computed when you pay.

Short pieces ship. Long sticks do not go in a box, so anything past the second shipping band goes to freight — quoted by email before anything is charged.

We hold a cut order at the counter for 30 days.