Lockstitch comparison
JACK A4C vs JACK S7: which lockstitch machine should you buy?
A side-by-side look at two lockstitch machines from our catalog: the specifications each one lists, where they differ, and which kind of production each suits. Both are used for shirts, wovens, garments.

JACK A4C
AI-integrated lockstitch machine running the Jack NTB control system with the Octopus "Nine-Brain" chip — direct-drive servo motor, auto thread trimmer, auto backtack and auto foot lift at up to 5000 s.p.m.

JACK S7
Jack’s current digitalized post-bed machine — three independent stepper motors and a 5-inch touch screen for accurate, noiseless roller-feed sewing.
Key differences
- JACK A4C lists an automatic thread trimmer; JACK S7 does not list one.
- Series: JACK A4C — Lockstitch (A-series, AI-integrated); JACK S7 — Post bed, digitalized.
- Availability: JACK A4C — Order on request; JACK S7 — Order on request. Call to confirm today's stock.
Specifications side by side
| Specification | JACK A4C | JACK S7 |
|---|---|---|
| Series | Lockstitch (A-series, AI-integrated) | Post bed, digitalized |
| Needle | DBx1, 11-18# | — |
| Number of threads | 2 | — |
| Max stitch length | 5mm | — |
| Presser foot lift (hand/auto) | 13mm / 6mm | — |
| Max sewing speed | 5000 s.p.m. | — |
| Control system | Jack NTB system with Octopus "Nine-Brain" AI chip | — |
| Motor | Direct-drive integrated servo motor | — |
| Feed | Computerized, auto-trimmer, auto backtack, auto foot lift | — |
| Availability | Order on request | Order on request |
| Motors | — | 3 stepper motors (needle bar + two rollers) plus main shaft motor |
| Screen | — | 5-inch multilanguage touch screen |
| Thread trimmer | — | Short-thread cut to 3mm precision |
| Perforation capacity | — | Penetrates 110+ layers of A4 paper |
| Connectivity | — | Industry 4.0 WiFi module (optional) |
| Best for | — | Shirts, jeans, non-woven bags, shoes, bags |
Highlighted rows differ. A dash means the catalog does not list that specification for the machine; ask us and we will confirm it.
Which one fits your work?
Choose the JACK A4C if…
AI-integrated lockstitch machine running the Jack NTB control system with the Octopus "Nine-Brain" chip — direct-drive servo motor, auto thread trimmer, auto backtack and auto foot lift at up to 5000 s.p.m.
- AI Nine-Brain chip
- Auto trim, backtack & foot lift
- Direct-drive servo motor
Choose the JACK S7 if…
Jack’s current digitalized post-bed machine — three independent stepper motors and a 5-inch touch screen for accurate, noiseless roller-feed sewing.
- 3 stepper motors + main shaft
- 3mm-precision thread trim
- 110+ layer perforation capacity
Swami Enterprises is an authorized JACK dealer and importer. Bring your own fabric to the Chanakya Place showroom and sew on both before you decide.
Questions buyers ask
What is the difference between the JACK A4C and the JACK S7?
JACK A4C lists an automatic thread trimmer; JACK S7 does not list one. Series: JACK A4C — Lockstitch (A-series, AI-integrated); JACK S7 — Post bed, digitalized. Availability: JACK A4C — Order on request; JACK S7 — Order on request. Call to confirm today's stock.
Which is better, the JACK A4C or the JACK S7?
It depends on your fabric, operation and daily volume. The JACK A4C is described as: AI-integrated lockstitch machine running the Jack NTB control system with the Octopus "Nine-Brain" chip — direct-drive servo motor, auto thread trimmer, auto backtack and auto foot lift at up to 5000 s.p.m. The JACK S7 is described as: Jack’s current digitalized post-bed machine — three independent stepper motors and a 5-inch touch screen for accurate, noiseless roller-feed sewing.
What is the price of the JACK A4C and the JACK S7?
Prices depend on the model, quantity and the day. Call +91 99713 36656 or request a quote for today's price on either machine.
Can I see both machines before buying?
Yes. Visit the showroom at Chanakya Place, New Delhi. Call +91 99713 36656 first so the team can confirm which models are on display and in stock.
Not sure which to pick?
Tell us your fabric, operation and daily volume. A specialist will recommend one, with today's price.