XINRISHENG 1574667726--64085709 Review

In any workshop that runs a milling machine — whether it is a full-size Bridgeport in a machine shop, a benchtop mill in a model engineer's garage, or a CNC router in a maker space — the end mills are among the most heavily used and most expensive consumables. A single high-quality tungsten carbide end mill can cost upwards of fifteen or twenty pounds, and once its cutting edges go dull, most people simply throw it in the scrap bin and reach for a new one. But what if you could bring that dull cutter back to a razor-sharp edge in minutes, extending its life by multiple resharpening cycles? That is exactly what a dedicated end mill sharpening machine does. Unlike a general-purpose bench grinder, which requires a steady hand and years of practice to get consistent results, these machines use preset angle guides and a diamond grinding wheel to restore the primary and secondary relief angles precisely — giving you factory-fresh cutting geometry without the factory price tag. For any workshop that goes through more than a few end mills a month, a sharpener can pay for itself in saved tooling costs faster than you might expect.

End mill sharpening machines sit in a specialised niche between a universal tool and cutter grinder — which costs thousands and takes up a square metre of floor space — and trying to hand-grind a cutter on a bench wheel, which rarely ends well. These dedicated sharpeners are designed to do one job and do it quickly: restore the cutting edges on two-flute, three-flute, and four-flute end mills with repeatable angles. They typically use a diamond-impregnated grinding wheel, which cuts tungsten carbide cleanly without the wheel wear you would get from a conventional aluminium oxide stone. When evaluating a sharpener in this class, the most important factors are the range of cutter diameters it can handle, the accuracy and repeatability of the angle settings, and the quality of the grinding wheel — because a wheel that runs out of true will produce scalloped edges instead of sharp ones.

In this review we look at a benchtop end mill sharpener powered by a 1,000-watt motor. We will examine its grinding capabilities, the range of cutter sizes and geometries it can handle, the build quality, and the practical value for workshops of different sizes. By the end, you will know whether this machine deserves a spot next to your milling machine or whether your tooling budget would be better spent on replacements.

Driven by a 1,000-watt electric motor running at approximately 5,000 RPM, this sharpener uses a diamond grinding wheel to restore the cutting edges on end mills ranging from 4 mm to 13 mm in diameter — covering the vast majority of cutters used on benchtop and mid-size milling machines. It can handle two-flute, three-flute, and four-flute end mills, which encompasses slot drills, standard end mills, and roughing cutters. The machine runs on standard 220-volt mains power — a 110-volt option is also available, but you must confirm which version you are ordering. The grinding process uses a single diamond wheel, which means you do not need to swap wheels between different grinding operations — the machine's fixturing handles the various relief angles.

The sharpener uses preset angle guides to control the grinding geometry automatically rather than relying on the operator's skill. The primary cutting edge is ground at a fixed angle, with separate settings for the first relief angle at 6°, the secondary relief at 20°, and a tertiary angle at 30°. These three angles work together to give the cutting edge both sharpness and strength — the primary relief prevents rubbing, while the secondary and tertiary angles provide chip clearance without weakening the cutting edge. The fixture holds the end mill at the correct orientation relative to the wheel, and the operator simply advances the cutter into the wheel using the built-in slide mechanism. According to the manufacturer, the process is simple enough that no special skills are required — a claim that will appeal to workshops without a dedicated tool grinder on staff.

In terms of everyday usability, the machine is a benchtop unit weighing approximately 17 kg, which gives it enough mass to stay put during operation without bolting down. The diamond wheel is a significant advantage over conventional abrasive wheels: diamond cuts tungsten carbide without generating excessive heat, reducing the risk of thermal cracking in the cutter, and the wheel itself wears very slowly compared to aluminium oxide. The operation cycle per end mill is relatively quick — once the cutter is mounted in the fixture and the angle is set, each flute can be ground in seconds. A four-flute end mill can therefore be resharpened in a couple of minutes, turning what used to be a throwaway item back into a usable tool. For a workshop that dulls several end mills per week, the time savings alone justify the bench space.

The machine is designed for straightforward operation, but it is worth setting expectations realistically. While the manufacturer states that no skills are needed, there is still a learning curve: you need to understand how to mount the end mill correctly in the fixture, how to align the cutting edge with the wheel, and how much material to remove per pass. Taking too aggressive a grind can overheat the carbide and cause micro-cracks, while too light a touch wastes time. The single diamond wheel configuration simplifies the process but also means the same wheel handles all operations — if the wheel gets loaded with aluminium or damaged by a mishandled cutter, you will need to replace it. The machine includes the basic fixturing and one diamond wheel; spare wheels and additional collets or bushings for different shank diameters may need to be sourced separately.

The machine is sold under a generic Chinese brand name with no established support network in Europe. At time of writing there are no customer reviews available on the French marketplace, which means there is no real-world feedback on accuracy, durability, or whether the angle settings are truly precise or merely approximate. With a listed retail price that is significantly higher than most hobby-grade sharpeners, this product occupies a price bracket where you could alternatively buy a substantial supply of new end mills or look at entry-level universal tool grinders from established manufacturers. The spare parts situation is explicitly described as unavailable, so if the diamond wheel wears out or the motor fails, you are unlikely to find replacement components through official channels. The decision to buy comes down to a calculation: how many end mills do you dull per year, and how many resharpening cycles would this machine need to deliver before it has paid for itself?

This end mill sharpening machine is aimed at small machine shops, model engineering workshops, and serious hobby machinists who dull enough 4-13 mm end mills per month that resharpening them in-house delivers a meaningful cost saving over buying replacements.