The Bernardo MD 3550 E fixed-speed magnetic core drill offers core drilling capacities up to Ø 35 mm with a maximum depth of 50 mm, twist drill capacity up to Ø 13 mm, drill head travel of 170 mm, no-load speed of 810 rpm, a universal 19 mm Weldon shank for standard core drills, an electromagnet with an adhesion force of 16,000 N, and a 1600 W motor at 230V single-phase. It weighs 11 kg and has machine dimensions of 170 × 280 × 400 mm. It is suitable for metal fabrication, machine construction, the automotive industry, on-site work, and workshops. Manufactured in Austria, distributed in Italy by Krollit as an official Bernardo distributor since 2007.
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Core drilling capacity: Ø 35 mm × depth 50 mm
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Max twist drill: Ø 13 mm
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Head travel: 170 mm
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Spindle speed: 810 rpm
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Magnet adhesion force: 16,000 N
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Motor: 1600 W – 230V single-phase
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Weight: approx. 11 kg
Who uses the MD 3550 E and for what
The Bernardo MD 3550 E is a portable magnetic core drill sized for mechanical workshops, metal fabricators, and construction sites. Fixed speed 810 rpm: simple and reliable configuration for standard use on typical materials and diameters. For workshops that primarily work structural steel with standard core drills, the fixed speed is correctly sized, avoiding electronic complexity and the costs of an inverter. The electromagnet with 16,000 N adhesion force ensures secure fastening on steel structures even in vertical or overhead positions, with a safety belt/chain included as standard. Its 11 kg weight and compact dimensions (170 × 280 × 400 mm) make it transportable to construction sites in a case or plastic container, without the need for pallet jacks or cranes. In Krollit customers' workshops, the MD 3550 E is chosen by metal fabricators, automotive workshops, steel structure manufacturers, industrial maintenance personnel, and on-site installers.
Its place in the Bernardo range
The Bernardo magnetic core drill range is organized by core drilling capacity (max diameter and depth) and by drive type. The range includes 10 models divided into 3 families:
E Family (fixed speed): MD 3550 E (Ø 35 mm), MD 3850 (Ø 38 mm), MD 4055 (Ø 40 mm), MD 5050 E (Ø 50 mm). Suitable for workshops with repetitive standard operations on known materials.
VD Family (Digital Variable Speed): MD 3550 VD (Ø 35 mm), MD 5050 VD (Ø 50 mm), MD 6050 VD (Ø 60 mm), MD 9875 VD (Ø 98 mm). Continuously adjustable speed for adaptation to the material, suitable for workshops with a variety of operations.
M Family (multi-gear/multifunction): MD 5075 with 2 gears (Ø 50 mm × 75 mm depth), TPC 1000 multifunction with tapping up to M18.
The MD 3550 E is sized for workshops with standard daily use. For workshops that alternate different materials (mild steels, hardened steels, aluminum), the corresponding VD version offers greater flexibility: for the MD 3550 E, the VD equivalent is the MD 3550 VD. The advantage of the E version lies in its simpler construction (fewer electronic components) and lower cost.
Krollit Logistics and Support
Bernardo shipping in 5-9 business days (7 days to Southern Italy). Weighing 11 kg, it is shipped in a case/plastic container and can be easily handled by one person, even on-site. Weldon 19 mm core drills, chucks, adapters, and original Bernardo spare parts are available from stock with 3-5 business day shipping. Customer support available in Italian.
Who the MD 3550 E is for
| Profile |
Compatibility |
Reason |
| Passionate hobbyist |
Adequate |
Semi-professional machine for occasional use on steel structures. Works on 230V single-phase domestic power, 11 kg weight manageable by one person. |
| Metal fabricator with daily use |
Recommended |
Ø 35 mm capacity and fixed speed 810 rpm sized for standard structural steels. Reliability of a simple configuration without complex electronic components. |
| On-site installer |
Recommended |
11 kg weight and compact dimensions (170 × 280 × 400 mm) make it portable. 16,000 N magnetic force for secure fastening on vertical structures. |
Not suitable for: core drilling beyond Ø 35 mm (consider models MD 5050, MD 5075, MD 6050 VD or MD 9875 VD); deep core drilling beyond 50 mm (the MD 5075 with 75 mm depth or MD 9875 VD with 75 mm depth are correctly sized); workshops with a variety of materials requiring different speeds (the corresponding VD version offers greater flexibility); non-magnetic structures (aluminum, non-magnetic stainless steel): the electromagnet will not adhere; continuous industrial use at high rates (magnetic core drills are sized for intermittent use).
Working capacity
| Specification |
Value |
| Max core drilling diameter |
Ø 35 mm |
| Max core drilling depth |
50 mm |
| Max twist drill diameter |
Ø 13 mm |
| Drill head travel |
170 mm |
Speed and tool holder
| Specification |
Value |
| Spindle speed |
810 rpm |
| Weldon shank |
19 mm |
| Distance Weldon - base |
145 mm |
Magnetic base
| Specification |
Value |
| Magnetic adhesion force |
16,000 N |
| Magnetic base dimensions |
165 × 80 × 50 mm |
Motor and power supply
| Specification |
Value |
| Motor power |
1600 W |
| Voltage |
230V |
| Power supply |
Single-phase |
Dimensions and weight
| Specification |
Value |
| Machine dimensions (L × W × H) |
170 × 280 × 400 mm |
| Weight |
approx. 11 kg |
Compliance
| Specification |
Value |
| Marking |
CE |
Standard equipment
- Bernardo MD 3550 E magnetic core drill
- Plastic transport case
- Safety belt/chain for vertical and overhead use
- User manual in Italian
- Service tool kit
Frequently asked questions
What materials does the MD 3550 E electromagnet work on?
Only on magnetic ferrous materials: structural steel, iron, carbon steels. It does not work on aluminum, non-magnetic stainless steel, or non-ferrous materials.
The electromagnet creates the magnetic field that fixes the machine to the structure: without ferrous material, fastening is impossible. For working on aluminum or non-magnetic stainless steel, fixed column drills or dedicated mechanical clamping systems are needed. For most standard metal structures (fabrication, frames, profiles), the electromagnet is the fastest and most reliable fastening system.
Can I use the core drill in a vertical or overhead position?
Yes, with the included safety belt/chain. The 16,000 N magnetic force is sized for fastening in any position, but safety always requires additional mechanical restraint.
The electromagnet holds the machine even during a momentary power interruption for the seconds needed to prevent falls, but in case of prolonged interruption (torn cable, blackout), the safety belt/chain is the only reliable system. Standard safety procedures ALWAYS require mechanical restraint in addition to the electric magnet, regardless of the nominal adhesion force.
Does the MD 3550 E have automatic lubrication?
Not integrated. For prolonged core drilling on hard steels, it is recommended to manually apply a metalworking lubricant to the tool before starting the hole.
Manual lubricant application is less convenient than the automatic lubrication of higher-end versions, but for intermittent artisanal use, it is manageable. The difference is noticeable in series production: with automatic lubrication, cutters last 3-4 times longer. For workshops with regular consumption of core drills, consider a model with internal lubrication.
Is the 19 mm Weldon shank a universal standard?
Yes. The 19 mm Weldon shank is the international standard for core drills: most commercial cutters (Karnasch, Magbohrer, Rotabroach, BDS, etc.) use this shank. All cutters have a 19 mm Weldon pin for quick fastening via a side set screw.
For workshops with cutters of other brands or standards, adapters can be used. For future investments, the 19 mm Weldon shank is the most widespread choice with the largest market offering. Original Bernardo cutters are in 19 mm Weldon shank and available from stock with 3-5 business day shipping.
How much power does the motor consume during intermittent use?
The 1600 W motor typically consumes 1.6-1.8 kWh per actual hour of operation. In intermittent artisanal use (1-2 minutes per hole, pauses between holes), the average consumption is 0.3-0.5 kWh/hour.
The motor only runs during the actual cutting of the hole; it is off between holes. For workshops with significant electricity costs, consumption is negligible. The core drill is an electrically efficient machine: the nominal power is only engaged during the actual working minutes. For intensive continuous use, a standard industrial meter is recommended.
