9 Best Spring Clamps in Bulk (November 2026)

The best spring clamps in bulk include the Amazon Basics 20-Piece Steel Spring Clamp Set for an everyday workshop supply, the SWANLAKE 16-Piece 6 inch Spring Clamp for repeated 6-inch clamp work, and the Online Best Service Lot of 24-6 inch Spring for the largest heavy-duty pack.

On this page (8 sections)

1. How we chose the best spring clamps in bulk
2. The best spring clamps in bulk for workshop use
3. Which spring clamp pack size should you choose?
4. Should you buy matching or mixed-size spring clamps?
5. What should you check before buying spring clamps in bulk?
6. Are smaller spring clamps useful for woodworking?
7. Can bulk spring clamps work for backdrops and tarps?
8. Final verdict on the best spring clamps in bulk

The best spring clamps in bulk for most workshops are the Amazon Basics 20-Piece Steel Spring Clamp Set. It combines 20 steel clamps with two compact jaw openings, so you can keep several holding points ready for glue-ups, crafts, repairs and general shop work.

Bulk spring clamps save time when a project needs many hands at once. They can hold parts while glue dries, secure fabric or backdrops, keep tarps in place and support temporary setup work.

For these lighter jobs, compare light-duty spring clamps.

This guide compares steel, plastic and nylon options by pack size, clamp size, jaw opening, materials and the kind of work each set fits best. For a broader look at woodworking clamps, see our complete category guide.

Our picks at a glance

1. 1
   Best for an everyday workshop supply

   Amazon Basics 20-Piece Steel Spring Clamp Set

   9.7/10 our score

   See it on Amazon
2. 2
   Best for repeated 6-inch clamp work

   SWANLAKE 16-Piece 6 inch Spring Clamp

   9.7/10 our score

   See it on Amazon
3. 3
   Best for the largest heavy-duty pack

   Online Best Service Lot of 24-6 inch Spring

   9.5/10 our score

   See it on Amazon

4. 4

   EQUIPTZ Spring Clamps for Woodworking

   Best for mixed-size project work
   Check it
5. 5

   WORKPRO 20-Piece Steel Spring Clamps

   Best for compact steel clamp sizes
   Check it
6. 6

   ELEAD 20-Piece 4-inch Spring Clamps for Woodworking/Backdrop

   Best for matching 4-inch clamps
   Check it
7. 7

   ACOSEA 30 Pcs 3.5 Inch Black Small

   Best for the most small clamps
   Check it
8. 8

   FASTPRO 20-Pack 4-Size Nylon Plastic Spring Clamps

   Best for four-size variety
   Check it
9. 9

   Quamate 6 Pack 6 inch Heavy Duty

   Best for a small wide-jaw set
   Check it

How we chose the best spring clamps in bulk

The best bulk spring clamp set gives you enough pieces for the job without forcing you into sizes you rarely use. We compared pack counts, jaw openings, clamp lengths, body materials, pad designs and handle features against common woodworking, craft, backdrop and outdoor uses.

Our score weighs specs, features and buyer feedback against what you're shopping for. A high score here means the set offers a useful combination of quantity, size coverage and practical holding features for bulk buying.

A matching pack works well when every holding point needs similar reach. A mixed-size kit is more useful when you switch between small parts, medium boards and wider materials.

Spring clamps are not a substitute for every clamp type. For more control over pressure and reach, compare these picks with our guide to the best spring clamps for woodworking.

The best spring clamps in bulk for workshop use

The Amazon Basics set is the strongest general choice, while the SWANLAKE and Online Best Service packs suit larger jaw openings. The remaining sets make more sense when you need mixed sizes, matching 4-inch clamps or a high count of small clamps.

1

Amazon Basics 20-Piece Steel Spring Clamp Set: Best for an everyday workshop supply

9.7/10Our score

• 20-piece set
• 15 clamps with 3/4 in jaw opening
• 5 clamps with 1 in jaw opening
• Nickel-coated steel with PVC-coated tips and handles

This set gives most workshops a useful mix of smaller spring clamps in one box. PVC-coated tips help protect surfaces while PVC-coated handles add grip.

See it on Amazon

Pros

• 20 clamps in 2 jaw sizes
• Non-marking PVC-coated tips
• Tempered-steel springs

Cons

• No larger jaw opening than 1 in
• Mostly made up of the smaller size

The Amazon Basics 20-Piece Steel Spring Clamp Set is a strong starting point for a general workshop. It includes 15 clamps with 3/4-inch jaw openings and 5 clamps with 1-inch jaw openings, so most of the set is aimed at close holding points.

The smaller clamps reach into tight joints, while the five larger ones cover slightly thicker pieces. Nickel-coated steel and tempered-steel springs suit repeated shop use.

PVC-coated tips help protect the surface, and PVC-coated handles give a non-slip hold. Pressure near the jaw tips helps the clamps bite where you place them.

This mix works well for small glue-ups, craft assemblies, photo backdrops and everyday repairs. It is less suitable for thick boards because the largest jaw opening is 1 inch.

Keep the set in a drawer or pouch for quick access. Wipe the tips clean after glue work so the coating can still grip.

Choose this set for a familiar compact layout with plenty of pieces. For wider jaws, the SWANLAKE, Online Best Service or Quamate options are better matches.

2

SWANLAKE 16-Piece 6 inch Spring Clamp: Best for repeated 6-inch clamp work

9.7/10Our score

• 16-piece set
• 6 in clamp length
• 2.4 in jaw opening
• Nickel-plated steel with rubber-covered handles

Sixteen matching 6-inch clamps suit projects where you want similar reach and jaw capacity at every holding point. The 2.4-inch opening handles thicker work than compact craft clamps.

See it on Amazon

Pros

• Wide 2.4 in jaw opening
• 16 matching clamps
• Rubber-covered handles

Cons

• Less size variety than mixed kits
• Larger clamps take more storage space

The SWANLAKE 16-Piece 6 inch Spring Clamp is best for projects that need a group of matching clamps with more reach. Each clamp is 6 inches long and has a 2.4-inch jaw opening, which is wider than the compact 3/4-inch and 1-inch options.

That wider opening changes what you can hold in daily use. It reaches around thicker boards, layered fabric and outdoor materials that would exceed a small craft clamp.

Nickel-plated steel gives the clamps a metal body, while rubber-covered handles provide a more secure grip. The arc handle design helps you squeeze with less hand strain during a long setup.

The set suits woodworking, tarp securing, pool cover installation, photography backdrops and other holding tasks. Matching lengths make it easier to space clamps evenly along a seam or edge.

Sixteen matching clamps make placement easier when you want similar pressure points around one project. You can plan the layout in advance instead of sorting by size at each step.

The trade-off is less size variety, so this pack is more specialized than a mixed spring clamp kit. Small fine work may still need a compact set for closer placement.

Pick it when a 2.4-inch opening covers your usual material thickness. For an even wider 3-inch opening and 24 matching clamps, consider the Online Best Service pack.

3

Online Best Service Lot of 24-6 inch Spring: Best for the largest heavy-duty pack

9.5/10Our score

• 24-piece set
• 6 in clamps
• 3 in jaw opening
• Nickel-plated steel with soft grips and jaw pads

This is the biggest pack here, with 24 matching 6-inch clamps and a 3-inch jaw opening. It fits large glue-ups, backdrop work and projects that need many wide holding points.

See it on Amazon

Pros

• 24 clamps in one pack
• 3 in jaw opening
• Soft grips and jaw pads

Cons

• One clamp size only
• May be more than a small project needs

The Online Best Service Lot of 24-6 inch Spring is the best bulk option when you need the largest number of matching wide-jaw clamps. It includes 24 6-inch clamps with 3-inch jaw openings.

That count and opening suit big layouts. You can hold a long glue-up, a backdrop, a tarp or a trellis line without running short halfway through.

Nickel-plated steel gives the clamps a metal construction. Soft grips on the handles and jaw areas help with handling and surface contact, while hanging holes support storage or anchoring during use.

The pivoting jaw pads can adjust to uneven surfaces for a closer match. That helps when plywood, fabric or outdoor material does not sit perfectly flat.

The 24-piece count is useful for large glue-ups, backdrop stands, fabric work, tarps and greenhouse or trellis projects. A single 6-inch size keeps the setup consistent, but it does not give you smaller clamps for fine work.

Store the set where the hanging holes are actually useful. A peg, rail or hook keeps the clamps visible and stops them tangling in a loose box.

Choose this set when the job needs many wide holding points. For a smaller quantity of the same 6-inch, 3-inch-opening format, the Quamate set is easier to store.

4

EQUIPTZ Spring Clamps for Woodworking: Best for mixed-size project work

9.3/10Our score

• 20-piece set
• 4 clamps at 6 in
• 6 clamps at 4 in
• 10 clamps at 3 in
• Non-detachable jaw pads

The 6-inch, 4-inch and 3-inch mix covers small parts, medium work and broader holding points without buying separate kits. The jaw pads are held in place rather than designed to fall off.

See it on Amazon

Pros

• Three clamp sizes
• 20 clamps total
• Soft rubber handles

Cons

• Only 4 clamps in the largest size
• Plastic body may not suit every heavy-duty task

The EQUIPTZ Spring Clamps for Woodworking are best when one kit needs to cover several project sizes. The 20-piece set includes 4 clamps at 6 inches, 6 at 4 inches and 10 at 3 inches.

That spread gives you a choice at the bench. Use the 3-inch clamps for small parts, the 4-inch clamps for middle work and the 6-inch clamps when you need extra reach.

Its plastic body uses an anti-rust electrophoretic-coated manganese steel spring. Soft rubber handles add grip, and the jaw pads are designed to stay attached during use.

Non-detachable pads matter in practice. You do not want to stop a glue-up to hunt for a pad that popped off under pressure.

The 3-inch group gives you plenty of smaller clamps for crafts and light assemblies. The four 6-inch clamps add reach for wider work, while the 4-inch group fills the middle.

The sturdy box helps with transport between a workshop, studio or home. Keep the sizes grouped inside so you can find the right length without sorting every time.

This is a practical choice for a mixed workshop, photography setup or household tool box. If every clamp needs to be steel-bodied, choose one of the metal sets instead.

5

WORKPRO 20-Piece Steel Spring Clamps: Best for compact steel clamp sizes

9.0/10Our score

• 20-piece set
• 15 clamps with 3/4 in jaw opening
• 5 clamps with 1 in jaw opening
• Zinc-coated steel with PVC-coated tips and handles

WORKPRO follows the same useful 15-and-5 size split as a compact shop set. Its steel construction and coated contact points fit small woodworking, repair and backdrop tasks.

See it on Amazon

Pros

• 20-piece steel set
• Two compact jaw openings
• Tempered-steel springs

Cons

• No wide-jaw option
• Mostly 3/4-inch clamps

The WORKPRO 20-Piece Steel Spring Clamps are a compact steel option with a familiar two-size layout. The set includes 15 clamps with 3/4-inch jaw openings and 5 with 1-inch jaw openings.

That layout is easy to learn. The smaller clamps handle thin parts and close spots, while the larger five cover a step up in thickness.

Zinc-coated steel provides the body, and tempered-steel springs support repeated opening and closing. PVC-coated tips help protect surfaces, while the coated handles provide a more secure grip.

Point of pressure near the jaw tips helps hold material firmly at the contact point. That is useful when you need a small assembly to stay aligned while glue sets.

Use this pack for woodworking, repairs, photo backdrops and general DIY tasks where a 1-inch opening is enough. Its main limitation is the same compact range that makes it easy to store.

The set fits a small drawer or a compact tool box. That makes it a good backup set for a bench, a craft table or a repair kit.

Choose WORKPRO when you want a steel 20-piece set with two small jaw sizes. If you want a similar count with a different brand or a broader mixed-size layout, compare the Amazon Basics and EQUIPTZ picks.

6

ELEAD 20-Piece 4-inch Spring Clamps for Woodworking/Backdrop: Best for matching 4-inch clamps

9.0/10Our score

• 20-piece set
• 4 in clamps
• Nickel-plated steel
• Rubber-covered handles

Twenty matching 4-inch clamps make a simple choice when a project needs many similar clips. Nickel-plated steel suits woodworking, backdrops, pool covers and tarp work.

See it on Amazon

Pros

• 20 matching clamps
• Nickel-plated steel
• Rubber-covered handles

Cons

• No mixed sizes
• Jaw opening is not stated

The ELEAD 20-Piece 4-inch Spring Clamps are best when you need many matching clamps at one middle size. All 20 clamps are 4 inches, so you can create even holding points without sorting several lengths.

A uniform size simplifies planning. You can space clamps along a backdrop, a tarp edge or a glue line and expect the same reach at each point.

Nickel-plated steel gives the clamps a metal construction, and rubber-covered handles support handling. The clamps suit woodworking, backdrop stands, pool covers, tarps, home decor and industrial tasks.

That metal body helps outdoors as well as in the shop. Nickel plating resists rust, which matters when clamps move between indoor jobs and damp or dusty outdoor work.

A matching 4-inch pack is easier to plan around than a mixed kit when your work uses similar materials each time. You also know exactly how many clamps you have left for the next project.

The trade-off is that the jaw opening is not stated, so measure your workpieces and confirm the fit before ordering. Check the thickness first, especially on layered fabric or stacked boards.

Choose ELEAD for a uniform 20-clamp setup. For known jaw openings, the Amazon Basics, SWANLAKE and Quamate sets provide clearer size information.

7

ACOSEA 30 Pcs 3.5 Inch Black Small: Best for the most small clamps

8.5/10Our score

• 30-piece set
• 3.5 in clamps
• 1.7 in maximum opening
• Nylon body with heat-treated spring

Thirty small clamps give you the highest piece count in this group. They fit crafts, models, photography and light woodworking where a 1.7-inch opening is enough.

See it on Amazon

Pros

• 30 clamps in one pack
• Fixed jaw pads
• Rotating jaw pads

Cons

• Smaller 1.7 in maximum opening
• Nylon body is not a steel body

The ACOSEA 30 Pcs 3.5 Inch Black Small Spring Clamps give you the highest count in this group. The 30 nylon clamps have a maximum 1.7-inch opening, making them useful for crafts, models, photography, tarp work and smaller woodworking tasks.

Thirty pieces give you spare capacity. You can spread clamps across several small assemblies at once or keep a few in different work areas.

The nylon body keeps this set distinct from the steel packs. Heat-treated springs provide the clamping action, while the jaw pads are fixed with a pin and can rotate to meet different angles.

Rotating pads help on uneven or angled pieces. They let the jaw sit flatter on a model part or a craft piece instead of gripping on one edge.

Thirty pieces help when a project has many small holding points or when you want spare clamps in several work areas. The ergonomic handle pattern also helps prevent slippage during use.

The 1.7-inch maximum opening limits the set for thicker materials. It is a specialist small-clamp pack, not a replacement for wide-jaw sets.

Pick ACOSEA when quantity and compact size matter most. For a broader range of clamp lengths, the FASTPRO four-size pack is more flexible.

8

FASTPRO 20-Pack 4-Size Nylon Plastic Spring Clamps: Best for four-size variety

8.3/10Our score

• 20-piece set
• Four clamp sizes from 2-1/2 to 6-1/2 in
• Jaw openings from 1 to 3 in
• String storage bag

This kit spreads 20 clamps across four sizes, so it suits a workshop with varied small jobs. A string bag keeps the clamps together when you move between work areas.

See it on Amazon

Pros

• Four clamp sizes
• Jaw openings from 1 to 3 in
• Storage bag included

Cons

• Plastic construction
• Fewer matching clamps at each size

The FASTPRO 20-Pack 4-Size Nylon Plastic Spring Clamps are best for a workshop that handles very different small jobs. The set includes clamps measuring 2-1/2, 3-1/2, 4-1/2 and 6-1/2 inches, with jaw openings from 1 to 3 inches.

That range covers a lot of daily work. The smallest clamps fit tight craft jobs, while the largest reach around thicker pieces up to a 3-inch opening.

The heavy-duty plastic clamps use metal springs and swivel pads that accommodate irregular surfaces. The included string bag keeps the 20-piece set together during storage or transport.

Swivel pads make a real difference on rough or uneven material. They spread contact instead of digging in at one point.

This four-size spread gives you more reach choices than a compact two-size pack. It also means fewer matching clamps at each size, which may matter during a large glue-up.

Count the split before you buy. The set includes 6-1/2 inch, 4-1/2 inch, 3-1/2 inch and 2-1/2 inch clamps, so plan around your most used size.

Choose FASTPRO when variety is more useful than a uniform pack. For 20 clamps concentrated at one size, ELEAD offers a simpler setup.

9

Quamate 6 Pack 6 inch Heavy Duty: Best for a small wide-jaw set

8.0/10Our score

• 6-piece set
• 6 in clamps
• 3 in jaw opening
• 30 lb clamping force

Six 6-inch clamps give smaller projects wide jaws without storing a large bulk pack. The 3-inch opening and stated 30 lb clamping force suit thicker materials and backdrop work.

See it on Amazon

Pros

• 3 in jaw opening
• 30 lb stated clamping force
• Rotating wide jaws

Cons

• Only 6 clamps
• No smaller sizes

The Quamate 6 Pack 6 inch Heavy Duty Spring Clamps are best for a smaller set of wide-jaw clamps. Each 6-inch clamp has a 3-inch jaw opening and a stated 30 lb clamping force.

Six clamps take up far less space than a 16 or 24 piece set. That suits a small drawer, a compact kit or a backup box for occasional wide work.

The body uses plastic, rubber and manganese steel. The wide rotating jaws can adjust their angle, while TPR rubber handles add slip resistance during use.

Rotating jaws help the clamp sit properly on uneven surfaces. That can improve holding on backdrops, pool covers and other flexible materials.

Six clamps are enough for a small glue-up, backdrop setup or household project that needs wider contact. This pack takes less storage space than the 16-piece and 24-piece 6-inch sets.

The sturdy box also helps with secure storage and transport. Keep the clamps together there instead of mixing them with smaller spring clamps.

Pick Quamate when you need wide jaws but do not want a large bulk quantity. For many matching clamps, choose the Online Best Service 24-piece set.

Which spring clamp pack size should you choose?

Choose a 20-piece pack for general workshop use, a 24-piece pack for large projects with many matching holding points, or a 30-piece pack when small clamps are useful across several work areas. A 6-piece pack is enough when you only need a few wide clamps.

Pack count matters most when the project has multiple joints or edges that need steady pressure. For a long glue-up, place clamps at regular points and keep extra clamps ready for sections that shift.

A large count does not automatically mean a better fit. Twenty small clamps may be less useful than six wide-jaw clamps if your material is too thick for a 1-inch opening.

Should you buy matching or mixed-size spring clamps?

Buy matching clamps when the same jaw opening and reach will work at every holding point. The SWANLAKE, Online Best Service and ELEAD sets each focus on one main clamp size.

Matching packs make layout faster. You can measure once, space the clamps evenly and know each one will reach the same thickness.

Replacement is simpler too. If you lose or wear out a few clamps, you can add the same size without changing your setup.

Choose a mixed-size kit when your projects change often. EQUIPTZ covers 3-inch, 4-inch and 6-inch sizes, while FASTPRO covers four lengths from 2-1/2 to 6-1/2 inches.

Mixed kits suit work that moves between crafts, repairs, backdrops and woodworking. You can pick a small clamp for thin parts and a larger one for a wider seam.

That flexibility can reduce separate purchases over time. One kit can cover jobs that would otherwise need two or three matching packs.

The trade-off is fewer clamps at the size you use most. If one size dominates your work, a matching pack is easier to organize and replace.

Storage also matters. A matching pack can go on a rail or in one drawer section, while a mixed kit may need sorting by length.

Think about your last few projects before you decide. If most used one size, buy matching.

If each job used a different size, buy mixed.

Jaw opening matters as much as clamp length. A mixed kit with a poor opening for your material may still leave you short.

Match the pack to your repeat work first. Add variety later if a single size starts to limit you.

What should you check before buying spring clamps in bulk?

Check the jaw opening first, then compare the clamp length, pack count, body material and pad design. The opening determines whether the clamp can reach around your workpiece, while length gives a rough sense of how much space it occupies in storage and use.

Look for coated tips or pads when the clamped surface could mark easily. Amazon Basics and WORKPRO use PVC-coated tips, while several larger picks describe soft or rubber jaw areas.

Consider storage if you are buying several dozen clamps. A large matching pack may need a dedicated drawer, while the FASTPRO set includes a string bag for carrying and storing its four sizes.

Before a glue-up, dry-fit the clamps and check that the handles remain accessible. For more detail, read our guide on how to use spring clamps.

Are smaller spring clamps useful for woodworking?

Small spring clamps are useful for thin parts, crafts, models and work that needs many close holding points. The ACOSEA, Amazon Basics and WORKPRO sets focus on compact openings, while the FASTPRO kit includes a 2-1/2-inch size with a 1-inch opening.

Their size is an advantage on small assemblies. A compact clamp can reach a joint that a 6-inch clamp would crowd or knock out of place.

They also let you place pressure close to the work. On thin parts, that close spacing can matter more than raw reaching power.

The main limitation is reach. They may not fit around thick boards or wide layered materials.

That limit shows up quickly on larger woodworking. A 3/4-inch or 1-inch opening cannot go around a thick board, no matter how many clamps you own.

Small clamps can still support bigger jobs in a supporting role. Use them for templates, spacers, small offcuts or fine alignment while larger clamps hold the main piece.

Keep glue and finish off the tips so the pads can grip cleanly next time. Choose small sets when your work is mostly thin material, and choose a mixed or wide-jaw set when thickness varies.

If your projects mainly use small parts, compare our guide to best small spring clamps for woodworking. If you need more reach, see the guide to best six-inch spring clamps.

A balanced bench often has both sizes. Match the clamp size to the material, not just to the pack count.

Can bulk spring clamps work for backdrops and tarps?

Yes, several sets here are suited to backdrops, tarps and pool covers, including the SWANLAKE, Online Best Service, EQUIPTZ, ELEAD and Quamate options. Wide jaw openings help hold thicker or layered materials.

Use enough clamps to spread the load instead of relying on one clamp at a single point. Check the material, wind and attachment surface before outdoor use, since spring clamps are only one part of a temporary setup.

For miter saw work, a purpose-built clamp may be a better fit than a general spring clamp. See our guides to the Best Miter Saw Clamp and How To Use Miter Saw Clamp?.

Final verdict on the best spring clamps in bulk

The Amazon Basics 20-Piece Steel Spring Clamp Set is the best all-around pick for a compact workshop because it combines 20 steel clamps with 3/4-inch and 1-inch openings. It gives you enough pieces for glue-ups, crafts, backdrops and repairs without forcing you into one size.

Choose SWANLAKE for 16 matching 6-inch clamps with a 2.4-inch opening. Choose Online Best Service when you need 24 clamps with 3-inch openings for large layouts.

Pick EQUIPTZ for three useful sizes in one 20-piece kit. Pick WORKPRO for a similar compact steel layout with PVC-coated tips.

Pick ELEAD for 20 matching 4-inch clamps when one middle size covers most of your work. Pick ACOSEA for the highest count of small clamps at 30 pieces.

Pick FASTPRO for four-size variety from 2-1/2 to 6-1/2 inches. If you only need a few wide clamps, Quamate gives you six 6-inch clamps with 3-inch openings.

Match the final choice to jaw opening first. The right opening will do more for your projects than a larger pack count alone.

Our top 3 picks at a glance

1. 1
   Best for an everyday workshop supply

   Amazon Basics 20-Piece Steel Spring Clamp Set

   9.7/10 our score

   See it on Amazon
2. 2
   Best for repeated 6-inch clamp work

   SWANLAKE 16-Piece 6 inch Spring Clamp

   9.7/10 our score

   See it on Amazon
3. 3
   Best for the largest heavy-duty pack

   Online Best Service Lot of 24-6 inch Spring

   9.5/10 our score

   See it on Amazon

Frequently asked questions

What are the best spring clamps in bulk for woodworking?

The Amazon Basics 20-Piece Steel Spring Clamp Set is the best all-around choice for many workshops because it includes 20 steel clamps in 3/4-inch and 1-inch jaw openings. Choose the EQUIPTZ set if you need 3-inch, 4-inch and 6-inch clamp sizes in one pack.

How many spring clamps do I need for a project?

Buy enough clamps to place holding points along the full workpiece, with closer spacing around joints and ends. A 20-piece pack suits repeated glue-ups, backdrops and shop tasks, while a 24-piece pack gives more matching clamps for a large setup.

Are steel or plastic spring clamps better?

Steel spring clamps generally suit buyers who want steel bodies and compact workshop sizes. Plastic and nylon clamps can make sense when you want lighter mixed-size kits, storage bags or small craft clamps.

Compare the jaw opening and contact pads with your work before choosing.

What jaw opening should bulk spring clamps have?

Choose a jaw opening that exceeds the thickness of the material you need to hold. The compact sets here open to 1 inch, while the wider picks reach 2.4 or 3 inches.

A mixed-size kit gives you more flexibility when projects vary.