Milling a workpiece clamped on a Magnaslot electropermanent chuck

Electropermanent workholding & lifting

Electric to switch. Permanent to hold.

Magnetic workholding and lifting equipment — made in India, sold to the world. One impulse clamps or grips; permanent magnetism holds, power or no power.

Since 1958
Sarda Magnets Group lineage
EP1874504
Magnaslot patent · designed in-house
160 N/cm²
Clamping force · 17 t on 400×600 mm
Worldwide
Supplied direct and through partners

The principle

One impulse.
Then zero power.

An electropermanent magnet spends electricity only in the instant of switching. Between switches the permanent magnets carry the whole load — which is why a power cut, a severed cable or a flat battery cannot drop your workpiece.

Step through it yourself, then cut the power and watch the hold survive.

Fig. 01 — Electropermanent switching Released
WORKPIECE / LOAD · · · · · · REVERSIBLE + PERMANENT MAGNET ASSEMBLY SUPPLY IDLE — 0 A

01 · Pulse on

A fraction-of-a-second current aligns the reversible poles.

02 · Hold

Permanent magnets carry the full force. No current at all.

03 · Pulse off

A reverse impulse cancels the field and releases instantly.

Product 01 · Magnetic workholding

Magnaslot

Electropermanent magnetic chuck — a complete magnetic machine bed.

Patent EP1874504 32 / 50 / 75 / 75T
Magnaslot 50 chuck, slotted solid-steel clamping face
Close-up of the slotted 50 × 50 mm pole face
Pole face · 50 × 50 mm, slots not epoxy
A workpiece machined on several faces in one setup
Five-face machining in one setup
Grinding a plate held on a Magnaslot chuck
Grinding · uniform hold, no chatter

Not a chuck bolted onto your machine — a magnetic bed machined from a single block of solid steel, its poles demarcated by cut slots. There is no epoxy filler to bulge, burn or leak, so the face spreads machining heat and keeps its accuracy. One impulse clamps the job; it then holds at zero power and shrugs off hot chips and coolant.

Holding force
≈ 160 N/cm² (>100 t/m²) — up to 17 t on 400 × 600 mm
Precision
Plane-parallelism ≤ 0.02 mm; ≤ 0.01 mm with pole extensions
Fail-safe
Full holding force retained on power loss
Auto-shimming
Spring-loaded pole extensions support bent or uneven stock
Supply
440 V AC standard; 220 / 380 / 400 / 480 V AC, 50–60 Hz on request
Applications
Milling, turning, drilling, grinding, gang milling, turbine blades, EDM (flat version)

No epoxy

No expansion, deformation, burning or leaking.

Five faces, one setup

Nothing clamped over the job; the cutter runs free.

Variable power

Dial the field down for thin workpieces.

75T is two chucks

T-slots clamp non-ferrous jobs mechanically.

Full model & pole-size table Open / close
ModelPole sizeMin. job thicknessMin. pole contactBest for
Magnaslot 3232 × 32 mm6 mm9 alternate polesSmall and thin components
Magnaslot 5050 × 50 mm10 mm8 alternate polesSmall–medium, rough parts
Magnaslot 7575 × 75 mm20 mm4 alternate polesMedium–large, heavy-duty cutting
Magnaslot 75T75 × 75 mm + T-slots20 mm4 alternate polesMixed ferrous / non-ferrous work

Standard plate sizes 300 × 430 mm to 600 × 990 mm, plus a reduced-density ECO range and custom sizes. Integrates with pallet-changing and FMS systems.

Product 02 · Magnetic lifting

SafeBat

Battery electropermanent lifting magnet — no cable, no external power.

BATEPM series SB200 to SB10000

A crane magnet with no cable and no external power. The battery is spent only on switching the magnet on and off — the load is then held by permanent magnetism, so it stays gripped even if the battery goes flat mid-lift. Dual poles handle flat plate and round bar alike.

Safety factor
3 : 1 SWL — load-verification display on SF models
Per charge
≈ 1,000 on / off switching cycles
Handles
Flat and round stock; long bars and sheets on the ACE beam
Switching
Automatic sequential switching by contactless relay; optional radio remote
Battery
Maintenance-free sealed cells, built-in charger with overcharge protection, low-battery warning
Applications
Stock yards, flame and plasma cutting tables, loading and unloading machine tools

Dead battery, held load

Power switches it; magnets hold it.

Flat and round

One magnet for plate and bar stock.

No trailing cable

Hooks onto any crane, moves anywhere.

Three power settings

Match the field to the sheet.

SafeBat SB950-SF with load-verification display
SafeBat lifting a round bar
Round bar · dual-pole grip
SafeBat lifting a rectangular plate
Plate · stock yard handling
BATEPM ACE multi-magnet beam lifting long bars
ACE beam · long bars and sheets
Full capacity table Open / close
ModelFlat loadRound loadLoad displayNotes
SB200200 kgOn requestLight plate and bar handling
SB500500 kgOn requestGeneral machine-shop lifting
SB950950 kgOn requestHeavy plate
SB950-SF950 kgOn requestYesLoad verification before the lift
SB10001,000 kgOn requestOn requestPlate handling
SB30003,000 kgOn requestOn requestHeavy plate and billets
SB50005,000 kgOn requestOn requestHeavy plate and billets
SB1000010,000 kgOn requestOn requestHeaviest single-magnet lifts
EPMBL beamup to 1,500 kgOn requestSheets 500–4,000 mm, from 3 mm thick
EPMB beamup to 10,000 kgOn requestHeavy plate and long stock

Round-stock capacities depend on diameter and surface condition — send us the job and we will confirm the safe working load.

Where to buy

Order direct, or through your regional partner

Both products are designed and built by us in India and supplied worldwide. In India and across most markets you buy directly from our team; in Europe, the United States and South-East Asia our partners sell and support the same machines under their own brands. Anywhere else, write to us and we will ship.

India
Shree Magnets

Buy directly from us. Pricing, sizing and technical support come from our own engineers.

Send an enquiry →
Germany · Europe
Assfalg GmbH

Sales, technical support and supply across Europe for both products. Deutsche Anfragen bitte an Assfalg.

assfalg-metal.com →
United States
Magswitch

Our US partner for magnetic workholding and lifting.

Ask for a US contact →
Singapore · SE Asia
Lifton Magnets

Regional supply and service for South-East Asia.

Ask for a regional contact →

The company

Inventor-led magnetic engineering

Shree Magnets Pvt. Ltd. carries forward a line of work that began with the Sarda Magnets Group in 1958 — among India's first industrial magnet makers. Today we are an independent, founder-led company designing our own electropermanent machines in Kolkata and shipping them worldwide.

The Magnaslot chuck is protected by patent EP1874504 and was developed here, not licensed in. Installations include heavy-engineering plants such as BHEL.

Exploded 3D view of the Magnaslot chuck construction
Magnaslot construction — solid steel top plate, reverse-pole magnet assembly
01

Designed

Our own electropermanent designs, engineered in-house and patented.

02

Solid-steel construction

Machined steel working faces instead of epoxy — built for real machining conditions.

03

Export-grade, made in India

The same machines our partners sell in Germany and the US ship to Indian shops direct.

04

Talk to the engineers

Technical answers come from the people who build the magnets, within one business day.

Enquiry

Tell us the job

Machine, workpiece, load, quantity — whatever you have. A technical requirement, a volume enquiry or a distribution partnership; we reply within one business day.

Company
Shree Magnets Pvt. Ltd.
Works
Sodepur Barasat Road, Murugacha, P.O. Jugberia, P.S. Ghola, Kolkata 700110, West Bengal, India

Which product?

European buyers: enquiries may be routed to Assfalg GmbH, our partner for Europe.