McMaster-Carr logo
    Filter by
    System of Measurement
    Compression Spring Type
    Export Control Classification Number (ECCN)
    Industrial Info Snippet
    DFARS Specialty Metals
    Industrial Info Compare
    Maximum Temperature
    Loop Type
    Specifications Met
    Mount Type
    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)
    74 Products

    Extension Springs

    The farther you stretch these springs, the harder they pull to bring the two ends back together. They're commonly used to tension cable, return an air cylinder to its starting point, or hold a door closed.
    Loop End—The most secure attachment method. With fully closed loops, there's no risk of slipping off.
    Hook End—Hook into closed holes, such as hanger bolt eyes. These springs work best when kept under tension, as they're more likely to slip off than loop-end springs when tension is released. Also known as machine hook ends.
    Elongated-Hook End—With deeper hooks than standard hook end springs, these are less likely to slip off. However, they’re more prone to breaking if overstretched.
    Straight-Wire End—Bend the long, straight ends into custom loops and hooks.
    Spring Steel—Strong and resilient, but best suited for dry environments since moisture will cause these springs to rust.
    Minimum Load—The amount of force required to start extending the spring.
    Maximum Load—The amount of force required to fully extend the spring.
    Load,
    lb.
    Lg.
    OD
    Wire
    Dia.
    Extended Lg.
    @ Max. Load
    Min.
    Max.
    Spring Rate,
    lbf/in
    Pkg.
    Qty.
    Pkg.
    Hook End
    Image of Product. Front orientation. Extension Springs. Hook End.
     
    Spring Steel
    1.75"0.75"0.105"2.04"12.844.3108.52600000000000
    3"0.75"0.105"3.822"12.844.338.3600000000000
    3.438"0.75"0.105"4.454"12.844.331600000000000
    3.813"0.75"0.105"4.975"12.844.327.136000000000000
     
    Elongated-Hook End
    Image of Product. Front orientation. Extension Springs. Elongated-Hook End.
     
    Spring Steel
    2 3/8"0.281"0.047"2.765"3.4411.7521.3260000000000000
    2 1/2"0.313"0.023"5.52"0.151.20.3460000000000000
    3 1/2"0.25"0.041"4.04"2.618.3510.6760000000000000
    3 3/4"0.563"0.072"4.21"4.1317.629.4430000000000000
    4"0.25"0.035"4.49"1.425.267.8760000000000000
    5 1/4"0.5"0.08"5.94"9.5127.7426.2730000000000000
    5 5/8"0.719"0.047"14.625"0.484.590.4610000000000000
    5 3/4"0.375"0.054"7.932"3.513.444.691000000000000
    5 3/4"0.437"0.054"9.022"2.6411.362.721000000000000
    5 3/4"0.5"0.062"8.442"3.5214.684.251000000000000
    6"0.25"0.041"7.802"2.549.363.931000000000000
    8 1/4"0.438"0.063"10.25"2.5712.086.0410000000000000
    8 1/2"0.468"0.054"10.08"2.3110.365.221000000000000
    10 1/4"0.75"0.091"12.24"7.3125.649.193000000000000
     
    Elongated-Hook End × Loop End
    Image of Product. Front orientation. Extension Springs. Elongated-Hook End × Loop End.
     
    Spring Steel
    1 5/8"0.25"0.039"1.895"1.957.2919.4260000000000000
    2"0.313"0.041"2.54"1.736.438.760000000000000
    5"0.563"0.072"6.29"5.0817.69.7330000000000000
    5 1/2"0.375"0.062"6.31"6.0617.9414.6230000000000000
     
    Hook End × Straight-Wire End
    Image of Product. Front orientation. Extension Springs. Hook End × Straight-Wire End.
     
    Spring Steel
    8 1/2"0.75"0.094"13.5"4.520.517.110000000000000
    17 1/2"0.75"0.063"23"2.6914.352.615000000000000
    18 1/2"0.813"0.094"20"10.6240.0926.735000000000000
     

    Cut-to-Length Compression Springs

    Image of Product. Side1 orientation. Compression Springs. Cut-to-Length Compression Springs.
    Image of Attribute. Front orientation. Contains Annotated. Cut-to-Length Compression Springs.
    Always be ready for the perfect fit. These springs are extra long to cut a custom length whenever you need it. Their open ends make cutting easier but prevent them from standing on their own. You’ll need to install them in a hole or over a shaft, or grind the ends flat.
    Spring Steel—Strong and resilient, but best suited for dry environments since moisture will cause these springs to rust.
    Spring Rate—To determine the spring rate of a cut spring, first multiply the spring rate given by the spring's original length, then divide the result by the cut length (in inches).
    Lg.
    OD
    ID
    Wire
    Dia.
    Max.
    Load
    Spring Rate,
    lbf/in
    End
    Type
    Pkg.
    Qty.
    Pkg.
    Spring Steel
    12"0.184"0.138"0.023"Not Rated0.67Open300000000000000
    12"0.206"0.154"0.026"Not Rated0.85Open30000000000000
    12"0.229"0.171"0.029"Not Rated0.96Open30000000000000
    12"0.254"0.19"0.032"Not Rated1.2Open30000000000000
    12"0.278"0.208"0.035"Not Rated1.3Open30000000000000
    12"0.328"0.246"0.041"Not Rated1.8Open30000000000000
    12"0.375"0.293"0.041"Not Rated1.5Open3000000000000
    12"0.38"0.284"0.048"Not Rated2.5Open30000000000000
    12"0.432"0.324"0.054"Not Rated3Open3000000000000
    12"0.5"0.374"0.063"Not Rated4.5Open3000000000000
    12"0.576"0.432"0.072"Not Rated5.6Open3000000000000
    12"0.64"0.48"0.08"Not Rated6.6Open3000000000000
    12"0.732"0.548"0.092"Not Rated8.8Open30000000000000
    12"0.844"0.632"0.106"Not Rated12Open30000000000000
    12"0.964"0.722"0.121"Not Rated14Open30000000000000
     

    Cut-to-Length Extension Springs

    Image of Product. Front orientation. Extension Springs. Cut-to-Length Extension Springs.
    Image of Attribute. Front orientation. Contains Annotated. Extension Springs. Cut-to-Length Extension Springs.
    Keep these springs on hand so you can cut the right length whenever you need it. Bend their straight-cut ends into custom loops or hooks.
    Spring Steel—Strong and resilient, but best suited for dry environments since moisture will cause these springs to rust.
    Minimum Load—The amount of force required to start extending the spring.
    Spring Rate—To determine the spring rate of a cut spring, first multiply the spring rate given by the spring's original length, then divide the result by the cut length (in inches).
    Lg.
    OD
    Wire
    Dia.
    Min. Load,
    lb.
    Spring Rate,
    lbf/in
    Pkg.
    Qty.
    Pkg.
    Straight-Cut End
     
    Spring Steel
    12"0.13"0.016"0.240.0930000000000000
    12"0.141"0.018"0.310.133000000000000
    12"0.16"0.02"0.390.163000000000000
    12"0.184"0.023"0.480.193000000000000
    12"0.206"0.026"0.60.243000000000000
    12"0.229"0.029"0.740.413000000000000
    12"0.25"0.032"0.930.373000000000000
    12"0.328"0.041"1.510.593000000000000
    12"0.375"0.048"2.090.8330000000000000
    12"0.437"0.054"2.570.9830000000000000
    12"0.5"0.063"3.521.3730000000000000
    12"0.964"0.121"13.095.1230000000000000
     

    Coil Lock Washers

    Image of Product. Front orientation. Lock Washers. Coil Washer.
    Washers flatten under pressure and push against the nut or screw to stop it from backing out. The double coil adds more tension than split lock washers for a tighter hold on materials that contract and expand, such as plastic and wood. These washers are reusable a handful of times, but their holding power decreases with each use.
    Corrosion-Resistant Galvanized Steel—These washers combine the strength of steel with the rust resistance of stainless steel. They're an alternative to 18-8 stainless steel in wet and outdoor environments, but they won't hold up to salt water and chemicals.
    For Screw
    Size
    ID
    OD
    Thk.
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Corrosion-Resistant Galvanized Steel
    3/8"
    		0.381"0.680"0.094"ASME B18.21.1500000000000000
    1/2"
    		0.507"0.869"0.125"ASME B18.21.110000000000000
    5/8"
    		0.634"1.073"0.156"ASME B18.21.110000000000000
    3/4"
    		0.759"1.265"0.188"ASME B18.21.110000000000000
     

    Tool Balancers

    Image of Product. Front orientation. Tool Balancers. Tool Balancers, Spring-Latch-Clip Tool Attachment.

    Spring-Latch-Clip

    Tool Attachment

    Suspend your tool for a weightless feel and movement with minimal effort. Tool balancers are good for minimizing fatigue in applications that require continuous tool use. Choose a load capacity that is sufficient for the total load you'll place on the tool balancer. This includes the tool plus any fittings, hose, or power cords.
    With Cable Lock—Cable lock allows you to lock the cable at set positions to avoid accidental adjustments. Tug on the cable to release the lock.
    Swiveling-Ring Hanger—Swiveling hangers rotate 360°.
    Balancers
    Secondary
    Restraints
    Wt.
    Cap., lb.
    Cable
    Hanger
    Min.
    Max.
    Travel,
    ft.
    Dia.
    Material
    Type
    Opening
    Size
    Ht. When
    Retracted
    Housing
    Material
    Each
    Each
    With Cable Lock
     
    Spring-Latch-Clip Tool Attachment
    456051/8"Galvanized SteelSwiveling Ring1 1/4"20 3/4"Aluminum
    		000000000000000000000000000
     

    Split Lock Washers

    Image of Product. Front orientation. Lock Washers. Split-Lock Washer.
    Stop nuts and screws from loosening due to mild vibration. As you tighten, the uneven ends bite into the nut or screw so it won't back out. While they're not as vibration resistant as other lock washers, they are a great fit for electrical panels, light fixtures, and other light duty assemblies. Split lock washers are not reusable, and they only work with fasteners that have right-hand threads.
    Corrosion-Resistant Galvanized Steel—These washers combine the strength of steel with the rust resistance of stainless steel. They're an alternative to 18-8 stainless steel in wet and outdoor environments, but they won't hold up to salt water and chemicals.
    For Screw
    Size
    ID
    OD
    Thk.
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    Corrosion-Resistant Galvanized Steel
    1/4"
    		0.260"0.487"0.062"ASME B18.21.110000000000000000
    5/16"
    		0.322"0.583"0.078"ASME B18.21.11000000000000000
    3/8"
    		0.385"0.705"0.094"ASME B18.21.11000000000000000
    7/16"
    		0.450"0.776"0.109"ASME B18.21.1250000000000000
    1/2"
    		0.512"0.869"0.125"ASME B18.21.1500000000000000
    5/8"
    		0.641"1.073"0.156"ASME B18.21.1250000000000000
    3/4"
    		0.766"1.265"0.188"ASME B18.21.12500000000000000
    7/8"
    		0.894"1.459"0.219"ASME B18.21.1100000000000000
    1"
    		1.024"1.656"0.250"ASME B18.21.1100000000000000
    1 1/4"
    		1.280"2.036"0.312"ASME B18.21.1500000000000000
    M6
    		6.5 mm11.8 mm1.5 mm to 1.7 mmDIN 127B500000000000000
    M8
    		8.5 mm14.8 mm1.9 mm to 2.1 mmDIN 127B5000000000000000
    M10
    		10.7 mm18.1 mm2.0 mm to 2.4 mmDIN 127B5000000000000000
    M12
    		12.7 mm21.1 mm2.3 mm to 2.7 mmDIN 127B250000000000000
    M16
    		17.0 mm27.4 mm3.3 mm to 3.7 mmDIN 127B100000000000000
    M20
    		21.2 mm33.6 mm3.8 mm to 4.2 mmDIN 127B10000000000000
     
    back to top