Bernardo Leather Honing Wheel for NTS 200 – Ø 200 × 30 mm, center Ø 12 mm
Leather wheels for sharpening and fine honing represent an essential step in the preparation and maintenance of cutting tools. Unlike abrasive grinding wheels that aggressively remove material, leather allows for a mirror finish and the application of fine abrasive paste for precision sharpening.
In the context of the NTS 200 lathe, this wheel is used for the final stages of sharpening high-speed steel (HSS) tools. The 200 mm diameter and 12 mm center ensure constant peripheral speed and robust mounting.
Distinctive features of the Bernardo product:
- Adhesive, homogeneous natural leather across the entire surface
- Prepared to accept fine abrasive paste (aluminum oxide, diamond)
- Quick mounting with standard M12 thread compatible with NTS 200 spindles
- Low price and weight compared to imported alternatives
Who is the Bernardo NTS 200 sharpening system with leather wheel suitable for?
| Profile |
Suitable? |
Reason |
| Craftsman / small workshop (metal parallel lathes) |
Ideal |
On-site sharpening of HSS tools reduces replacement costs and maintains constant precision on medium productions. Cycle time 30-60 seconds per tool, ROI in 20-30 sharpenings. |
| Industrial maintenance and spare parts |
Ideal |
Leather wheel for mirror finish is standard for restoring cutting speed on worn tools. Allows reconditioning in 5 minutes instead of external order of 2-3 days. |
| Job-shop workshop (diversified machining) |
Adequate |
Conditional utility: requires operator experienced in manual sharpening (learning curve 20-40 hours) and availability of fine abrasive paste. Marginal value if short production runs. |
Not suitable for:
- Workshops without experience in manual sharpening — risk of tool damage and operator frustration
- Operations on non-ferrous tools (aluminum, copper) or solid carbide — leather is damaged by excessively hard materials, alternative solution recommended
Technical specifications
Dimensions and mounting
| Parameter |
Value |
| External diameter |
200 mm |
| Width |
30 mm |
| Bore / center diameter (thread) |
Ø 12 mm (M12 × 1.75 mm) |
| Net weight |
10 kg |
| Shape tolerance |
According to EN ISO 1302 (natural leather, ±1 mm permissible) |
Material and composition
| Parameter |
Value |
| Material |
Vegetable-tanned natural leather |
| Adhesion to support |
Permanent bonding to phenolic core |
| Surface grain |
Fine, prepared for abrasive paste (grit 240-400) |
Compliance and markings
| Parameter |
Value |
| Manufacturer |
Bernardo GmbH, Linz (Austria) |
| Bernardo item code |
05-20601 |
| Compliance |
Not subject to Machinery Directive 2006/42/EC (accessory component) |
| Country of origin |
Austria |
Frequently asked questions
What is the difference between a fine and a coarse leather wheel for the NTS 200?
The fine wheel (this product, Ø 200 × 30 mm) is for the final sharpening stages and produces a mirror finish. The coarse version is for roughing heavily worn tools. Krollit recommends having both in stock for complete reconditioning cycles.
Details: fine = 240-400 grit paste, speed 1,200-1,500 rpm, time 30-60 seconds per tool. Coarse = 120-180 grit paste, speed 800-1,000 rpm, time 15-30 seconds per roughing phase.
Can I use the Bernardo 05-20601 wheel on machines other than the NTS 200?
Theoretically yes, if the spindle accepts M12 × 1.75 mm thread. In practice, Bernardo designs each wheel for the specific speeds and loads of the target machine. Check with the alternative machine manufacturer before mounting.
How do I prepare and maintain a leather sharpening wheel?
Before first use, "activate" the leather with a low-speed rotating wire brush to raise the nap. Apply fine abrasive paste powder (Bernardo 05-20602 or Al₂O₃ 240 grit powder). After each sharpening session, brush off residue with a dry cloth. Every 100 hours of use, renew the paste and brush again to maintain effectiveness.
What is the lifespan of a 200 × 30 mm leather wheel?
With regular sharpening and maintenance, 3-5 years. Typical deterioration: leather hardens, loses abrasive paste adhesion, requires more frequent activation. Symptom: tools do not achieve a mirror finish even with fresh paste applied.
What warranty does Bernardo offer on this wheel?
Bernardo warranty 24 months against manufacturing defects (leather, broken phenolic core, damaged thread). Does not cover natural wear or deterioration from improper use (excessive speed, humidity, UV light exposure).
Is the Bernardo 05-20601 wheel compatible with abrasive pastes from other brands?
Yes. Being natural leather, it accepts any standard abrasive paste (120-400 grit aluminum oxide, corundum). Bernardo does not limit suppliers. Advice: check grit size compatible with tool steel hardness (HSS = 240-400 grit; carbide = consult supplier).
Can I mount the 05-20601 wheel horizontally (not vertically) on the NTS 200?
No. The design of the leather wheel and the NTS 200 spindle mounting assume a vertical alignment for operator safety and stability during tool contact. Horizontal mounting exposes the leather to uneven crushing.
What tools can I sharpen on this wheel?
Single-edge HSS (roughing tools, drills, shoulder end mills), medium-hard construction steel tools, some brazed inserts. Not suitable for solid carbide (too hard, damages leather), synthetic diamond, ceramics. For carbide, consult Bernardo for alternative solutions.
