Suture Sizes and Uses Chart in Canada vs the US: Which Size for Which Wound?
What does the number on a suture pack actually mean?
A suture size is a diameter, not a strength rating. The scale is the United States Pharmacopeia convention, and it runs in two directions. Below zero the zeros stack up: 5-0, 6-0, 7-0 and finer, each step producing a thinner strand. At zero the scale turns, and 0, 1, 2 and 3 get progressively thicker. US labelling and Canadian labelling both use this scale, and an absorbable poly(glycolide/l-lactide) suture is defined in US regulation by reference to United States Pharmacopeia requirements, so the number on the pack means the same thing on both sides of the border.
Which suture size goes with which tissue?
Use the size chart as a starting point for stock planning, then let the tissue and the tension decide.
| USP size | Nominal diameter | Typical use | Common material families |
|---|---|---|---|
| 11-0 and 10-0 | 0.01 to 0.02 mm | Ophthalmic and microsurgical repair | Nylon, polypropylene |
| 9-0 and 8-0 | 0.03 to 0.04 mm | Ophthalmic and microsurgical repair, fine nerve work | Nylon, polypropylene |
| 7-0 and 6-0 | 0.05 to 0.07 mm | Small vessel repair, hand, nail bed and facial skin | Nylon, polypropylene, fast-absorbing gut |
| 5-0 and 4-0 | 0.1 to 0.15 mm | Larger vessel repair, skin closure on hands, limbs and face, tendon repair | Absorbable monofilament, silk, nylon |
| 3-0 and 2-0 | 0.2 to 0.3 mm | Thick skin, fascia, muscle and tendon repair | Absorbable braided, nylon |
| 0 and 1 | 0.35 to 0.4 mm | Fascia closure and drain stitches | Absorbable braided, polypropylene |
| 2 and above | over 0.5 mm | Large tendon repair, thick fascial closure, orthopaedic work | Absorbable braided, stainless steel |
Two rules sit behind the chart. A strand should be the smallest one that holds the tissue without cutting through it, and a wound under tension takes the next size up rather than a tighter knot.
Do Canadian and US clinics use the same suture size labels?
On sizing, yes. The regulatory frame around the product is where the two markets separate.
| Item | Canada | United States |
|---|---|---|
| Device classification | Medical devices must hold a device licence before they can be sold | Class II, for example an absorbable poly(glycolide/l-lactide) suture under 21 CFR 878.4493 or a stainless steel suture under 21 CFR 878.4495 |
| Size labelling | USP size | USP size, written into the device identification for absorbable sutures |
| Special controls | Manufacturer quality system and labelling requirements | FDA special controls guidance for surgical sutures |
| Used needles | Into a sharps container; provincial rules and CSA Z316.6 shape container requirements | Into a sharps container under the OSHA bloodborne pathogens regulation |
| Reusable instruments | Needle holders and forceps fall under CSA Z314:23 reprocessing | Reprocessing instructions per cleared labelling |
Does an absorbable suture change the size you should pick?
Not the size, but the knot. Absorbability is a property of the material, while the size sets the diameter. A braided absorbable strand handles differently from a monofilament absorbable strand of the same size: the braid holds a knot with fewer throws, which suits a closure under tension, while the monofilament slides and needs more throws but passes through fine skin with less drag. Absorbable sutures also carry their own removal question, because the wound does not need a return visit for suture removal when the strand is designed to lose strength over a set period.
How do you close a wound when sutures are not the right tool?
Superficial lacerations under low tension, and wounds in children, are often closed without a needle. Wound closure strips and tissue adhesives cover a large share of that work, and both need a clean, dry, approximated wound edge to hold. Knowing where a strip stops working matters: strips do not close a gap under tension, and they do not control bleeding from a vessel.
How do you dispose of used suture needles?
- Drop the needle and any unused length straight into a sharps container at the point of use.
- Keep the container within arm's reach of the procedure, and close it at the fill line rather than pressing contents down.
- Follow provincial or state rules for the container, and the CSA Z316.6 requirements that Canadian container procurement is measured against.
- Reprocess needle holders, forceps and scissors under your CSA Z314:23 instrument reprocessing workflow before they are reused.
What should a clinic stock alongside its suture selection?
- Wound closure strips for low-tension lacerations and for supporting a sutured line.
- Sterile 12-ply gauze sponges for wound bed preparation and dressing changes.
- Cloth medical tape to secure dressings over a closed wound.
- A stocked sharps container sized to the procedure room, replaced at the fill line.
Ordering for a clinic, lab or care home? Wholesale and multi-site ordering covers case pricing and account setup, and the B2B wholesale collection lists the lines stocked for institutional buyers.
Wound care stock is decided as a set rather than one item at a time. The wound care collection groups the closure, dressing and fixation lines a procedure room draws on together, which makes a quarterly par level easier to build than a list of single products.
References
- 21 CFR 878.4493 - Absorbable poly(glycolide/l-lactide) surgical suture (FDA classification, Class II) (checked 26 September 2026)
- 21 CFR 878.4495 - Stainless steel suture (FDA classification, Class II) (checked 26 September 2026)
- Using Absorbable Sutures for Traumatic Wound Closure to Avoid Additional Hospital Visits for Suture Removal (checked 26 September 2026)
- Oxford Medical Education - Suture sizes and suggested indications for their use (checked 26 September 2026)
Related Reading
- Wound Closure Strips: Sizes, Technique and When to Choose Them Over Sutures
- Steri-Strips vs Sutures: Closure Options and Aftercare
Frequently Asked Questions
What suture size is 3-0 in millimetres?
A 3-0 suture has a nominal diameter of about 0.2 mm, and a 2-0 about 0.3 mm. Moving one size step changes the strand diameter by roughly 0.05 to 0.1 mm, which is why the size, not the material, decides how much tension a closure can hold.
Is a thinner suture a higher number or a lower number?
Count the zeros. More zeros mean a thinner strand, so 6-0 is finer than 4-0. Once you pass size 0 the scale reverses and the numbers climb, so a 2 is thicker than a 0.
Which suture size is used on the face?
Facial skin is usually closed with 5-0 or 6-0, sometimes 7-0 on the eyelid and lip margin. The same wound on the back or a limb would normally take 3-0 or 4-0 because the tissue is thicker and under more tension.
Do Canadian clinics use the same suture size labels as US clinics?
Yes. Both markets label absorbable sutures to United States Pharmacopeia size conventions, and the US classification for an absorbable poly(glycolide/l-lactide) suture refers directly to USP requirements. The size scale does not change at the border; the licensing frame and the waste rules do.
What suture size is used for fascia closure?
Fascia is closed with 0 or 1 in most abdominal work, occasionally 2-0 in small sites. Fascia is under constant tension, so surgeons step up a size rather than trade it for a finer cosmetic result.
Last updated: September 2026. CliniEco Medical is a licensed medical device establishment (MDEL #35334).
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