McMaster-Carr logo
    Forward
    Enter e-mail addresses in the fields below
    Message
    Cancel
    Print
    How can we improve?
    Comments
    E-mail address (if you would like a response)
    19 Products

    Parallels

    Image of Product. Front orientation. Parallels.
    Elevate, support, and align workpieces in machining, grinding, and inspection setups. These parallels are precision ground to ensure accurate positioning in vises while providing additional clearance for cutting tools. Made of hardened steel, they withstand the wear and tear of shop-floor setups and heavy duty applications. To use, place a parallel against each vise jaw and rest the workpiece on top. You can also use these parallels as reference surfaces for measurement and alignment.
    4 Precision-Ground Sides—Precision ground on the top edge, bottom edge, and both faces.
    Tolerance
    Lg.
    Thk.
    Ht.
    Ht.
    Parallel
    Material
    Pair
    Starrett Parallels
     
    4 Precision-Ground Sides
    6"1/4"1/2"-0.0002" to 0.0002"-0.00005" to 0.00005"Hardened Steel00000000000000
    6"1/4"3/4"-0.0002" to 0.0002"-0.00005" to 0.00005"Hardened Steel0000000000000
    6"3/8"3/4"-0.0002" to 0.0002"-0.00005" to 0.00005"Hardened Steel0000000000000
    6"1/2"1"-0.0002" to 0.0002"-0.00005" to 0.00005"Hardened Steel0000000000000
     
    Other Parallels
     
    4 Precision-Ground Sides
    12"3/4"1"-0.0004" to 0.0004"-0.0002" to 0.0002"Hardened Steel0000000000000
    12"1"2"-0.0004" to 0.0004"-0.0002" to 0.0002"Hardened Steel0000000000000
     

    Sets of Parallels

    Keep multiple sizes of matched pairs on hand in one protective case. These parallels elevate, support, and align workpieces in machining, grinding, and inspection setups. They are precision ground to ensure accurate positioning in vises while providing additional clearance for cutting tools. Durable and wear resistant, parallels are made of hardened steel. They’re a rugged solution for shop-floor setups and heavy duty applications. To use, place a parallel against each vise jaw and rest the workpiece on top. You can also use them as reference surfaces for measurement and alignment.
    Inch
    Image of Product. Front orientation. Parallels. Sets of Parallels, Straight.

    Straight

    4 Precision-Ground Sides—Precision ground on the top edge, bottom edge, and both faces.
    Tolerance
    No. of
    Pairs
    Lg.
    Thk.
    Ht.
    Ht.
    Parallel
    Material
    Container
    Type
    Each
    Straight
     
    4 Precision-Ground Sides
    96"1/4"3/4", 7/8", 1", 1 1/8", 1 1/4", 1 3/8", 1 1/2", 1 5/8", 1 3/4"-0.0002" to 0.0002"-0.0002" to 0.0002"Hardened SteelPlastic Case000000000000000
    98"1/4"1", 1 1/4", 1 3/8", 1 1/2", 1 5/8", 1 3/4", 1 7/8", 2", 2 1/8"-0.0001" to 0.0001"-0.0001" to 0.0001"Hardened SteelPlastic Case0000000000000
    106"1/32"1/2", 5/8", 3/4", 7/8", 1", 1 1/8", 1 1/4", 1 3/8", 1 1/2", 1 5/8"-0.0001" to 0.0001"-0.0001" to 0.0001"Hardened SteelPlastic Case00000000000000
    106"1/8"1/2", 5/8", 3/4", 7/8", 1", 1 1/8", 1 1/4", 1 3/8", 1 1/2", 1 5/8"-0.001" to 0.001"-0.0002" to 0.0002"Hardened SteelPlastic Case00000000000000
     

    Sets of Adjustable Parallels

    Adjust these two-piece parallels to your exact height requirements. Loosen the one or two screws and slide the pieces in and out. When the desired height is achieved, tighten the screws. Parallels are precision ground and often used in pairs. Place a parallel against each vise jaw and rest your workpiece on top to raise it within the vise, allowing more clearance for cutting tools. Parallels also function as adjustable gauges for layout, setup, and inspection tasks.
    Inch
    Image of Product. Front orientation. Parallels. Sets of Adjustable Parallels.
    Image of Product. Front orientation. Parallels. Sets of Adjustable Parallels.
    4 Precision-Ground Sides—Precision ground on the top edge, bottom edge, and both faces.
    No. of
    Pieces
    Includes
    Thk.
    Material
    Container
    Type
    Each
     
    4 Precision-Ground Sides
    6One 3/8" to 1/2" High Parallel (6" Length)—0.0005" Tolerance
    One 1/2" to 11/16" High Parallel (6" Length)—0.0005" Tolerance
    One 11/16" to 15/16" High Parallel (6" Length)—0.0006" Tolerance
    One 15/16" to 1 15/16" High Parallel (6" Length)—0.0006" Tolerance
    One 1 5/16" to 1 3/4" High Parallel (6" Length)—0.0009" Tolerance
    One 1 3/4" to 2 1/4" High Parallel (6" Length)—0.0009" Tolerance    		1/8"SteelPlastic Pouch00000000000000
     

    Granite Inspection Parallels

    Image of Product. Front orientation. Inspection Parallels. Granite Inspection Parallels.
    Support and align workpieces for precise measuring and inspecting. Made of black granite, these inspection parallels won’t rust or warp from temperature changes, and they won’t scratch surfaces. Unlike metal inspection parallels, they’re also nonmagnetic, so they won’t interfere with sensitive electronic equipment. Made in pairs, these inspection parallels are precision ground to tight tolerances for matching flat surfaces on two or four sides. They come with a certificate traceable to NIST confirming their accuracy.
    4 Precision-Ground Sides—Inspection parallels with 4 precision-ground sides have a tight parallel tolerance on the top edge, bottom edge, and both faces.
    Inspection-Grade A Plate—Inspection Grade A inspection parallels are used for general inspections and quality-control work. They’re slightly less precise than Grade AA ones.
    Laboratory-Grade AA Plate—Laboratory Grade AA inspection parallels have the tightest tolerance for the highest level of accuracy. They’re best for inspections and quality-control work in calibration labs.
    Inspection-Grade A Plate
    Laboratory-Grade AA Plate
    Lg.
    Thk.
    Ht.
    Material
    Certificate Type
    Parallel
    Tolerance
    Pair
    Parallel
    Tolerance
    Pair
    Sold as Matched Pair
     
    4 Precision-Ground Sides
    6"3/4"1"Black GraniteAccuracy Certificate Traceable to NIST0.0001"000000000000000.00005"00000000000000
    12"1"2"Black GraniteAccuracy Certificate Traceable to NIST0.0001"00000000000000.00005"0000000000000
     

    Parallels for Magnetic Workholding

    Image of Product. Front orientation. Parallels. Parallels for Magnetic Workholding.
    Use with magnetic workholding chucks and plates to extend their holding power above the working surface. These parallels are laminated with 1/16"-thin layers of iron and stainless steel for a strong, consistent hold. Compared to parallels made from aluminum or brass, these are harder and more dent resistant, so they hold their shape over time. Each layer is entirely fused together with copper brazing, so you can machine these parallels without the layers separating. Note: Parallels are not magnetic on their own.
    Sold as Matched Pair—Manufactured and ground together to ensure they are parallel and square to each other with a tolerance of 0.0002".
    4 Precision-Ground Sides—Precision ground on the top edge, bottom edge, and both faces.
    Tolerance
    Sold
    Individually
    Sold as
    Matched Pair
    Lg.
    Thk.
    Ht.
    Ht.
    Parallel
    Material
    Each
    Pair
    4 Precision-Ground Sides
    6"1"2"-0.005" to 0.005"0.0002"Copper-Brazed Iron, Copper-Brazed Stainless Steel0000000000000000000000000000
    8"1"4"-0.005" to 0.005"0.0002"Copper-Brazed Iron, Copper-Brazed Stainless Steel0000000000000000000000000000
     
    back to top