Guida completa agli inserti in carburo a 35°: inserti di tornitura VBMT e VCMT per la lavorazione CNC di precisione
In precision CNC turning, the cutting insert is where the tool meets the metal. A wrong insert choice leads to poor surface finish, shorter tool life, and costly downtime. A right one transforms every pass into a predictable, repeatable result.
For machinists and manufacturing engineers working with steel, stainless steel, and cast iron, 35° carbide inserts offer a versatile solution for profiling, finishing, and semi-finishing operations. At GRAN INDUSTRIES SDN. BHD., we supply a comprehensive range of VBMT and VCMT carbide inserts, covering multiple grades and chip breakers to match a wide spectrum of turning applications.
In this guide, you will learn the difference between VBMT and VCMT insert geometries, how to select the right grade and chip breaker for your material, and why GRAN is a dependable source for carbide inserts in Malaysia and internationally.
What Are 35° Carbide Inserts and Why They Matter in CNC Turning
A 35° carbide insert is a diamond-shaped cutting tool with a 35-degree included angle, designed for turning operations that require access to tight contours, undercuts, and profile details. The acute angle lets the tool reach areas that wider-angle inserts — like 55° (DNMG) or 80° (CNMG) — simply cannot.
These inserts are typically positive-rake, which means they cut with lower cutting forces, reduced vibration, and better surface finish — especially important when machining thin-walled parts or long, slender workpieces.
- 35° acute angle — reaches tight contours and undercuts
- Positive rake geometry — lower cutting forces, smoother finishes
- Two cutting edges per insert — flip and reuse, doubling value
- Carbide construction — handles hard-to-machine materials including cold-rolled steel
VBMT vs VCMT: Understanding the Insert Designations
The ISO insert designation system tells you everything about geometry, tolerance, and clamping method. Here is how VBMT and VCMT break down:
| Letter | Meaning | VBMT | VCMT |
|---|---|---|---|
| V | Insert shape | 35° Diamond | 35° Diamond |
| B / C | Clearance angle | 5° (B) | 7° (C) |
| M | Tolerance class | M-class | M-class |
| T | Clamping / chip breaker | Cylindrical hole, single-sided | Cylindrical hole, single-sided |
The key difference is the clearance angle: VBMT has a 5° clearance, while VCMT offers a 7° clearance. The larger 7° clearance on VCMT reduces rubbing against the workpiece, which can be beneficial for softer materials or applications where minimising flank wear is critical.
Insert Grades Explained: HP1020, HP1050, HM2035, and HK3115
Carbide insert grade is the single most important factor for both tool life and surface quality. Each grade represents a specific carbide substrate and coating combination, optimised for particular workpiece materials and cutting conditions.
| Grade | Coating Type | Best For | Applicazioni |
|---|---|---|---|
| HP1020 | PVD (TiAlN-based) | Steel finishing | High-speed finishing on carbon and alloy steels; excellent wear resistance at elevated speeds |
| HP1050 | PVD (advanced multilayer) | Steel finishing at higher speeds | Optimised for harder steels and higher cutting speeds; enhanced thermal stability |
| HM2035 | CVD (MT-TiCN/Al₂O₃) | Stainless steel and cast iron | Semi-finishing to medium roughing; balanced toughness and wear resistance for ISO M and K materials |
| HK3115 | CVD (Al₂O₃-enhanced) | Cast iron | Dedicated cast iron grade with high hot hardness; resistant to abrasive wear in grey and nodular iron |
Rule of thumb: Choose PVD-coated grades (HP1020, HP1050) for sharp cutting edges on steel finishing. Choose CVD-coated grades (HM2035, HK3115) when heat resistance and longer tool life on stainless steel or cast iron are priorities.
Chip Breaker Selection: JHQ, MVL, SH, FML, SL1, and STF
Chip breaker geometry controls how material curls, breaks, and evacuates from the cutting zone. The right chip breaker turns stringy, dangerous chips into small, manageable fragments.
| Chip Breaker | Insert Type | Best Application | Cutting Range |
|---|---|---|---|
| JHQ | VBMT | Steel finishing | Light depths of cut, medium-to-high feed rates |
| MVL | VBMT | General steel turning | Light to medium depths, wide feed range |
| SH | VBMT | Heavy-duty steel | Medium-to-heavy depths, higher feed capability |
| FML | VCMT | Steel semi-finishing | Light-to-medium depths, versatile feed range |
| SL1 | VCMT | Steel & stainless semi-finishing | Medium depths, balanced chip control on mixed materials |
| STF | VCMT | General steel turning | Broad application range, good chip evacuation |
Selection tip: For pure finishing on steel, start with JHQ or HP1020. For semi-finishing across mixed materials including stainless steel, SL1 paired with HM2035 is a dependable starting point.
Material Compatibility: What These Carbide Inserts Can Machine
Our 35° carbide inserts are compatible with a wide range of workpiece materials, making them a versatile addition to any tool crib:
- Carbon and Alloy Steels — All grades deliver reliable performance. HP1020 and HP1050 excel in finishing.
- Stainless Steels — HM2035 is your go-to grade, with SL1 or FML chip breakers for semi-finishing.
- Cast Iron (Grey and Nodular) — HK3115 is purpose-built for this abrasive material, resisting flank wear at high cutting speeds.
- Cold-Rolled Steel — Carbide inserts handle this hard-to-machine material well, producing good surface finishes where HSS tools fall short.
- Aluminium, Brass, and Leaded Steels — While carbide lasts practically forever on these soft materials, the sharpest HSS tools still achieve the ultimate mirror finish. For production volumes where tool life matters more than a cosmetic finish, carbide is the smarter choice.
Why Choose GRAN for Your Carbide Insert Supply
GRAN INDUSTRIES SDN. BHD. is not simply a reseller. We are a manufacturing company with roots dating back to 2008 in Shenzhen, expanded production capacity in Sichuan since 2020, and a Malaysia-based international service platform established in 2025. This means three things for carbide insert buyers:
- Manufacturing depth — We understand cutting tools because we use them in our own CNC machining operations daily. Our recommendations come from practical experience, not catalogue descriptions.
- Competitive pricing — Carbide inserts start from RM 1.57 per piece, packaged in boxes of 10. At these prices, even prototype and small-batch shops can afford quality tooling.
- Structured international supply — Whether you are in Malaysia, Southeast Asia, or beyond, our Kuala Lumpur-based team provides clear communication, fast quotation, and dependable order follow-up.
Product Range Summary: VBMT and VCMT Carbide Inserts at a Glance
| Product | Type | Chip Breaker | Grades | Applicazione | Price (RM) |
|---|---|---|---|---|---|
| VBMT JHQ | Positive | JHQ | HP1020, HP1050 | Steel Finishing | 1.64 |
| VBMT MVL | Positive | MVL | HP1020, HP1050 | General Steel | 1.57 |
| VBMT SH | Positive | SH | HP1020, HP1050 | Heavy-Duty Steel | 2.80 |
| VCMT FML | Positive | FML | HP1020, HP1050, HM2035, HK3115 | Steel Semi-Finishing | 1.57 |
| VCMT SL1 | Positive | SL1 | HP1020, HP1050, HM2035, HK3115 | Steel & Stainless Semi-Finishing | 1.64 |
| VCMT STF | Positive | STF | HP1020, HP1050, HM2035, HK3115 | General Steel | 2.45 |
Carbide vs High-Speed Steel: When Each Makes Sense
A question that comes up repeatedly in machine shops: should I use carbide or HSS for this job? The honest answer is it depends on the material and the goal.
- Carbide excels on hard materials: Cold-rolled steel, alloy steels, stainless steel, and cast iron. It holds an edge longer, runs at higher cutting speeds, and handles interrupted cuts better than HSS.
- HSS wins on soft materials when finish is everything: On aluminium, brass, and leaded steels, a freshly ground HSS tool can produce a surface finish that carbide struggles to match. The trade-off is tool life — in production volumes, carbide’s longevity usually pays off.
- Carbide inserts eliminate sharpening downtime: When an edge wears, you index or replace the insert and keep cutting. No grinding, no resetting tool offsets. Over a shift, this difference compounds into real productivity gains.
How to Order Carbide Inserts from GRAN
Ordering is straightforward. Visit our carbide insert category page, select the insert geometry, grade, and chip breaker combination that matches your application, and add to basket. All inserts are packed 10 pieces per box.
If you need help selecting the right insert — or if you have a custom CNC machining project that requires specialised tooling advice — our engineering team is available at info@gran.my or by phone at +60 10-881 2868.
Conclusione
Choosing the right carbide insert is a decision that affects every part that comes off your CNC lathe. The 35° VBMT and VCMT inserts give you the geometry to reach tight features, the grade options to match your workpiece material, and the chip breaker variety to control your cutting process.
- Match the grade to the material: HP1020/HP1050 (PVD) for steel finishing; HM2035 (CVD) for stainless and mixed materials; HK3115 (CVD) for cast iron.
- Select the chip breaker by cutting depth: JHQ and FML for light finishing cuts; SL1 and STF for medium semi-finishing; SH for heavier stock removal.
- Choose VBMT or VCMT based on clearance needs: VBMT (5° clearance) for general work; VCMT (7° clearance) when minimising flank contact is beneficial.
At GRAN INDUSTRIES SDN. BHD., we combine manufacturing experience since 2008 with a Malaysia-based international service platform to deliver carbide inserts you can rely on — from single boxes for trial runs to bulk orders for production. Browse our full range here.
Frequently Asked Questions
Q: What is the difference between VBMT and VCMT carbide inserts?
A: The main difference is the clearance angle. VBMT has a 5° clearance angle, while VCMT has a 7° clearance. The larger clearance on VCMT reduces rubbing against the workpiece and is often preferred for softer materials or when flank wear management is critical. Both are 35° diamond-shaped, positive-rake, single-sided inserts with M-class tolerances.
Q: How many cutting edges does a 35° carbide insert have?
A: A 35° diamond-shaped insert has two usable cutting edges — one at each acute-angled corner. When one edge wears, you rotate the insert 180° and use the second edge. This effectively doubles the tool life per insert and eliminates the need for resharpening.
Q: Which carbide grade should I use for stainless steel turning?
A: For stainless steel, we recommend HM2035 — a CVD-coated grade that provides a good balance of toughness and wear resistance at the elevated temperatures typical of stainless steel machining. Pair it with the SL1 or FML chip breaker for semi-finishing applications.
Q: What carbide insert is best for cast iron machining?
A: HK3115 is the dedicated cast iron grade in our range. Its CVD coating with enhanced Al₂O₃ content provides high hot hardness and excellent resistance to the abrasive wear that cast iron (both grey and nodular) causes. Use it with VCMT inserts for semi-finishing operations.
Q: How much do GRAN carbide inserts cost?
A: Our 35° carbide inserts range from RM 1.57 to RM 2.80 per piece, sold in boxes of 10. This pricing is competitive for the Malaysian and Southeast Asian market. For bulk orders or OEM supply agreements, contact us at info@gran.my for a custom quotation.
Q: Can carbide inserts be used on aluminium?
A: Yes, carbide inserts work on aluminium, brass, and leaded steels and last practically forever on these materials. However, the absolute best surface finish on soft materials still comes from a sharp, well-ground HSS tool. For production environments where consistent tool life is more valuable than a cosmetic mirror finish, carbide is the better economic choice.
