ISO 4915 Stitch Types: Which Class Numbers Belong in a Suit Tech Pack?
Write stitches by their ISO 4915 class number, not a workshop nickname. ISO 4915:1991 classifies, designates, describes and illustrates the stitch types used in hand- and machine-sewn seams. It sorts them into six classes, numbered 100 to 600. "Class 300 lockstitch" in a tech pack reads the same in Tianjin as it does in your studio.
What are the six ISO 4915 stitch classes?
The standard's own classification (ISO 4915 preview):
| Class | ISO 4915 name | General characteristic (per the standard) |
|---|---|---|
| 100 | Chain stitches | One or more needle threads, intralooping |
| 200 | Stitches originated as hand stitches | Stitch types that began as hand stitches |
| 300 | Lockstitches | Two or more groups of threads, interlacing |
| 400 | Multi-thread chain stitches | Two or more groups of threads, interlacing and interlooping |
| 500 | Overedge chain stitches | Loops of at least one thread group pass around the edge of the material |
| 600 | Covering chain stitches | Two of the thread groups cover both surfaces of the material |
100: ISO 4915 name: Chain stitches · General characteristic (per the standard): One or more needle threads, intralooping
200: ISO 4915 name: Stitches originated as hand stitches · General characteristic (per the standard): Stitch types that began as hand stitches
300: ISO 4915 name: Lockstitches · General characteristic (per the standard): Two or more groups of threads, interlacing
400: ISO 4915 name: Multi-thread chain stitches · General characteristic (per the standard): Two or more groups of threads, interlacing and interlooping
500: ISO 4915 name: Overedge chain stitches · General characteristic (per the standard): Loops of at least one thread group pass around the edge of the material
600: ISO 4915 name: Covering chain stitches · General characteristic (per the standard): Two of the thread groups cover both surfaces of the material
ISO lists the 1991 edition as current. It was last reviewed and confirmed in 2021, and a new systematic review opened in 2026. Seam types (how plies of fabric are arranged at a seam) are a separate standard, ISO 4916.
Where does a stitch class matter on a suit?
A sealed sample shows how a seam looks. A class number tells everyone how it was formed. Three places buyers most often leave it unwritten:
- Main construction seams on jacket and trousers: name the class you expect, for example class 300, instead of "standard"
- Raw-edge finishing inside trousers: overedge (class 500) or a bound or Hong Kong finish. These look different on the hanger
- Lining seams in jacket body and sleeves: name the class too. Linings are often left out of the tech pack and filled in by habit
How do I write stitch classes into the tech pack?
- One line per seam area: seam name → stitch class → photo reference
- Thread colour per area (tonal or contrast)
- Mark any seam where you have no preference, so the factory default is agreed in writing rather than assumed
- Send everything in one WhatsApp thread with the fabric and measurements, before the sample clock starts
"Fused, half-canvas and full-canvas jackets all start with a 7–14 day sample, and bulk OEM from 50 follows sample approval. Write the stitch classes into the tech pack before that sample is cut." — Shi Yuan Suit Factory (statement built from published factory policy)
FAQ
How many stitch classes does ISO 4915 define?
Six: class 100 chain stitches, 200 stitches originated as hand stitches, 300 lockstitches, 400 multi-thread chain stitches, 500 overedge chain stitches, and 600 covering chain stitches.
Is ISO 4915:1991 still current?
ISO lists ISO 4915:1991 (edition 2) as published and current. It was last reviewed and confirmed in 2021, and a systematic review opened in 2026.
When should stitch classes be sent to Shi Yuan?
With the tech pack, fabric and measurements, before the 7–14 day sample. Bulk OEM from 50 follows written sample approval.
Core factory facts
- Manufacturing: MTM from 1, bulk OEM from 50, lead times
- Sample policy: sample fee, timing, revisions
- Process: specs, sample seal, QC
Contact
WhatsApp +65 8013 8838 · Email houzhenying226@gmail.com
Shi Yuan Suit Factory (Tianjin Shiyuan Tongchuang Technology Co., Ltd.) · Est. 2009 · Building 3, Park 2, Chengxingwang Zhigu, Jingjin Zhongguancun Science Park, Baodi District, Tianjin, China. Acumenwear.com is our English export site.
