McMaster-Carr logo
    Filter by
    System of Measurement
    Compression Spring Type
    U.S.–Mexico–Canada Agreement (USMCA) Qualifying
    Loop Type
    DFARS Specialty Metals
    Industrial Info Compare
    Export Control Classification Number (ECCN)
    Industrial Info Snippet
    Maximum Temperature
    Specifications Met
    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"12.844.3108.5269628K700000
    3"0.75"0.105"3.822"12.844.338.369628K290000
    3.438"0.75"0.105"4.454"12.844.33169628K410000
    3.813"0.75"0.105"4.975"12.844.327.1369628K4500000
     
    Elongated-Hook End
    Image of Product. Front orientation. Extension Springs. Elongated-Hook End.
     
    Spring Steel
    2 3/8"0.281"0.047"2.765"3.4411.7521.32696605K2300000
    2 1/2"0.313"0.023"5.52"0.151.20.34696605K4400000
    3 1/2"0.25"0.041"4.04"2.618.3510.67696605K2100000
    3 3/4"0.563"0.072"4.21"4.1317.629.44396605K2600000
    4"0.25"0.035"4.49"1.425.267.87696605K2200000
    5 1/4"0.5"0.08"5.94"9.5127.7426.27396605K2700000
    5 5/8"0.719"0.047"14.625"0.484.590.46109290K4500000
    5 3/4"0.375"0.054"7.932"3.513.444.69196605K540000
    5 3/4"0.437"0.054"9.022"2.6411.362.72196605K530000
    5 3/4"0.5"0.062"8.442"3.5214.684.25196605K510000
    6"0.25"0.041"7.802"2.549.363.93196605K550000
    8 1/4"0.438"0.063"10.25"2.5712.086.04109290K2100000
    8 1/2"0.468"0.054"10.08"2.3110.365.22196605K570000
    10 1/4"0.75"0.091"12.24"7.3125.649.19396605K100000
     
    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"1.957.2919.42696605K3100000
    2"0.313"0.041"2.54"1.736.438.7696605K3200000
    5"0.563"0.072"6.29"5.0817.69.73396605K3400000
    5 1/2"0.375"0.062"6.31"6.0617.9414.62396605K3500000
     
    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"4.520.517.1109290K2200000
    17 1/2"0.75"0.063"23"2.6914.352.6159290K4700000
    18 1/2"0.813"0.094"20"10.6240.0926.7359290K2400000
     

    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 Rated0.67Open396565K38000000
    12"0.206"0.154"0.026"Not Rated0.85Open396565K3700000
    12"0.229"0.171"0.029"Not Rated0.96Open396565K3600000
    12"0.254"0.19"0.032"Not Rated1.2Open396565K3500000
    12"0.278"0.208"0.035"Not Rated1.3Open396565K3400000
    12"0.328"0.246"0.041"Not Rated1.8Open396565K3300000
    12"0.375"0.293"0.041"Not Rated1.5Open396565K390000
    12"0.38"0.284"0.048"Not Rated2.5Open396565K3200000
    12"0.432"0.324"0.054"Not Rated3Open396565K310000
    12"0.5"0.374"0.063"Not Rated4.5Open396565K290000
    12"0.576"0.432"0.072"Not Rated5.6Open396565K280000
    12"0.64"0.48"0.08"Not Rated6.6Open396565K270000
    12"0.732"0.548"0.092"Not Rated8.8Open396565K2600000
    12"0.844"0.632"0.106"Not Rated12Open396565K2500000
    12"0.964"0.722"0.121"Not Rated14Open396565K2400000
     

    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"0.240.0931330K91000000
    12"0.141"0.018"0.310.1331330K9200000
    12"0.16"0.02"0.390.1631330K9300000
    12"0.184"0.023"0.480.1931330K9400000
    12"0.206"0.026"0.60.2431330K9500000
    12"0.229"0.029"0.740.4131330K9600000
    12"0.25"0.032"0.930.3731330K9700000
    12"0.328"0.041"1.510.5931330K9900000
    12"0.375"0.048"2.090.8331330K11100000
    12"0.437"0.054"2.570.9831330K11200000
    12"0.5"0.063"3.521.3731330K11300000
    12"0.964"0.121"13.095.1231330K11800000
     

    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 B18.21.1592353A11000000
    1/2"
    		0.507"0.869"0.125"ASME B18.21.1192353A1200000
    5/8"
    		0.634"1.073"0.156"ASME B18.21.1192353A1300000
    3/4"
    		0.759"1.265"0.188"ASME B18.21.1192353A1400000
     

    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
    		6644A4700000006652A21000000
     

    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 B18.21.110095160A210000000
    5/16"
    		0.322"0.583"0.078"ASME B18.21.110095160A2150000
    3/8"
    		0.385"0.705"0.094"ASME B18.21.110095160A2200000
    7/16"
    		0.450"0.776"0.109"ASME B18.21.12595160A2250000
    1/2"
    		0.512"0.869"0.125"ASME B18.21.15095160A2300000
    5/8"
    		0.641"1.073"0.156"ASME B18.21.12595160A2400000
    3/4"
    		0.766"1.265"0.188"ASME B18.21.12595160A25000000
    7/8"
    		0.894"1.459"0.219"ASME B18.21.11095160A2600000
    1"
    		1.024"1.656"0.250"ASME B18.21.11095160A2700000
    1 1/4"
    		1.280"2.036"0.312"ASME B18.21.1595160A28000000
    M6
    		6.5 mm11.8 mm1.5 mm to 1.7 mmDIN 127B5091169A31000000
    M8
    		8.5 mm14.8 mm1.9 mm to 2.1 mmDIN 127B5091169A32000000
    M10
    		10.7 mm18.1 mm2.0 mm to 2.4 mmDIN 127B5091169A33000000
    M12
    		12.7 mm21.1 mm2.3 mm to 2.7 mmDIN 127B2591169A34000000
    M16
    		17.0 mm27.4 mm3.3 mm to 3.7 mmDIN 127B1091169A3500000
    M20
    		21.2 mm33.6 mm3.8 mm to 4.2 mmDIN 127B191169A3600000
     
    back to top