Intro
The difference between a multi-tool that earns its keep and one that gathers dust in the bottom of a tool bag often comes down to one thing: the blade. A high-quality blade bites into material cleanly, tracks straight, and keeps its edge long after a budget alternative has gone blunt. This is especially true when cutting metal — a material that punishes poor-quality blades with immediate dulling, wandering cuts, and teeth that strip within seconds of touching a hardened bolt or steel profile. Investing in purpose-built metal-cutting blades from a manufacturer with deep expertise in the category is not just about getting a cleaner cut. It is about finishing the job without stopping to swap blades every few minutes, and about trusting that the blade will not fail halfway through a cut that you cannot restart. When the material is unforgiving, the blade needs to be even more so.
Generalities
FEIN is the company that invented the oscillating multi-tool — the original patent holder — and they have been refining both the tools and the blades for over five decades. When you buy FEIN blades, you are buying from the engineers who defined the category. This 'Best of Starlock Metal' 6-piece set is designed specifically for hardened and non-hardened metals, using a 60-tooth geometry and Starlock mounting interface. The blades measure 40 by 32 millimetres — a compact profile optimised for controlled plunge cuts and precision trimming in metal rather than fast, rough cutting in timber. This is a specialist metalworking accessory set, not a general-purpose blade pack.
This review examines the blade geometry and tooth count, how the Starlock mounting interface affects power transfer when cutting metal, real-world performance on hardened versus non-hardened steel, and whether FEIN's premium pricing — roughly €8.50 per blade — is justified by the performance and longevity compared to cheaper bimetal alternatives.
Description
The FEIN Best of Starlock Metal set contains six saw blades engineered exclusively for metal cutting — including both hardened and non-hardened steels. Each blade features a 60-tooth configuration across a compact 40 by 32-millimetre profile, which puts more teeth in contact with the material at any given moment than a coarser blade. The high tooth count means each tooth takes a smaller bite, reducing the cutting load per tooth and generating a smoother, more controlled cut with less vibration. For metalwork — where chatter and wandering can ruin both the cut and the blade — this dense tooth pattern is a significant advantage over coarser general-purpose blades.
The blades use the Starlock mounting interface, which FEIN co-developed with Bosch as the successor to the original OIS system that FEIN pioneered decades earlier. The Starlock 3D interface creates a deeper, more positive engagement between the tool and the blade than the older friction-fit OIS mount, and this matters particularly when cutting metal. Metal cutting generates higher lateral forces than wood or plastic, and a blade that works slightly loose during the cut will wander off the line, strip teeth, or snap entirely. The Starlock mount's resistance to these forces keeps the blade where it belongs throughout the cut.
FEIN manufactures these blades in Germany — not a marketing detail but a meaningful indicator of the precision grinding and quality control behind each unit. The tooth geometry is computer-modelled for the specific oscillation arc of Starlock-compatible multi-tools, meaning each tooth engages and clears the cut at the optimal point in the oscillation cycle. The blades are designed to handle the full hardness spectrum that a tradesperson encounters — from soft non-ferrous metals like copper and aluminium tubing, through standard steel profiles and bolts, up to hardened fasteners that would destroy a standard bimetal blade on the first cut. At 280 grams for the full set of six, they add negligible weight to a tool case.
The set is packaged as a compact card of six blades, making it easy to slide into a tool case or van rack without taking up significant space. The blades are individually accessible, so you can pull one out without disturbing the rest. For professional metalworkers, HVAC installers cutting ducting and brackets, automotive technicians trimming exhaust components and body panels, and plumbers cutting copper and steel pipe in tight spaces, six blades represents a practical working stock — enough to last through several jobs before needing to reorder. The Starlock Snap-In mechanism allows blade changes in seconds without touching the hot cutting surface.
The FEIN Best of Starlock Metal set holds an exceptional 4.8 out of 5 stars rating from 76 verified buyers — one of the highest satisfaction scores among all oscillating tool accessories. It ranks number 11 in the Oscillating Tool Accessories sub-category and number 3,355 overall in DIY and Tools, remarkable visibility for a niche consumable item. The set carries no manufacturer warranty, which is standard for consumable blades. At approximately €8.50 per blade, the pricing reflects the German manufacturing origin and the specialised metal-cutting tooth geometry — it is a premium consumable, not a budget bulk pack, and the value proposition rests on longevity and cut quality rather than upfront cost per blade.
Pros and cons
Pros
- Purpose-built for hardened and non-hardened metals — the 60-tooth geometry and specialised steel handle everything from soft copper to hardened fasteners that would destroy standard bimetal blades.
- 60-tooth dense tooth pattern delivers smoother, more controlled cuts in metal — each tooth takes a smaller bite, reducing vibration, chatter, and the risk of the blade wandering off the cut line.
- Made in Germany by FEIN, the company that invented the oscillating multi-tool — the blade geometry is optimised specifically for the oscillation arc of Starlock-compatible tools, not a generic one-size-fits-all design.
- Starlock 3D mounting interface provides superior blade retention during metal cutting — the deeper engagement resists the higher lateral forces that metal generates, keeping the blade locked in position.
- Exceptional user satisfaction — 4.8 out of 5 stars from 76 reviews and ranked number 11 in Oscillating Tool Accessories, reflecting consistent premium performance and longevity.
- Compact 40 by 32-millimetre blade profile is ideal for controlled plunge cuts and precision trimming in metal — not oversized for rough work, but sized for the detailed metal cutting that professionals actually do.
- Six-blade pack provides a practical working stock for professional metalworkers — enough to cover multiple jobs before reordering, without the bulk and cost of a larger pack where blades might sit unused for months.
Cons
- Premium pricing at roughly €8.50 per blade — significantly more expensive than generic bimetal alternatives, and the value only materialises if you regularly cut hardened metal where cheaper blades fail quickly.
- Specialised for metal only — not suitable for wood, plastic, or mixed-material cuts. Users need a separate set of blades for non-metal tasks, adding to the overall accessory investment.
- No manufacturer warranty — standard for consumable blades, but worth noting given the premium price point. A damaged or defective blade is your loss to absorb.
- Compact 40 by 32-millimetre size limits plunge depth compared to longer blades — adequate for most metal trimming and pipe cutting, but users needing deep plunge cuts in thick steel sections may need a larger blade profile.
- Only 76 reviews at the time of writing — while the 4.8-star average is impressive, the modest sample size means long-term durability across diverse metalworking applications is not yet widely documented.
Use cases
The FEIN Best of Starlock Metal 6-blade set is a premium, German-made metal-cutting accessory pack for professional metalworkers, HVAC installers, automotive technicians, and plumbers who use Starlock-compatible oscillating multi-tools and need reliable, long-lasting blades for hardened and non-hardened steel, copper, and aluminium.
Professional Metal Fabrication and Trimming
Trim steel profiles, cut bolts and threaded rod to length, and notch metal sections during fabrication work. The 60-tooth blade produces a clean edge that needs less filing than a coarser blade, and the Starlock mount keeps the blade tracking straight through the full cut.
Automotive Exhaust and Bodywork Repairs
Cut through rusted exhaust clamps, trim body panel sections, and slice seized fasteners during vehicle repairs. The blades handle hardened steel bolts that destroy generics, and the compact 40-millimetre width fits into the tight spaces around exhaust systems and engine bays.
HVAC Ducting and Bracket Installation
Trim galvanised ducting, cut mounting brackets, and notch steel framing during heating and ventilation installations. The six-blade pack provides enough stock for a full installation project, and the clean cutting action reduces the sharp burrs that cut hands and snag insulation.
Plumbing Pipe Cutting in Confined Spaces
Cut copper and steel pipe in tight corners where a pipe cutter cannot rotate — behind basins, inside cabinets, and against walls. The plunge-cutting capability of the oscillating blade lets you start the cut mid-pipe without needing access to the end, saving time on awkward plumbing repairs.
Hardened Fastener and Seized Bolt Removal
Cut through seized, rusted, or hardened fasteners during demolition and renovation work where an angle grinder would throw sparks into a finished room. The blades are designed to handle the hardness that destroys standard bimetal blades on the first cut, making them a problem-solver for renovation contractors.