Bosch Starlock MAX Oscillating Multi Tool Review

Solid, durable, powerful, minimal vibration, and with the fastest blade change on the market.

Bosch Starlock MAX Oscillating Multi Tool

Bosch Starlock MAX Oscillating Multi-Tool

Oscillating multi-tools are indispensable because of their flexibility – simply by changing accessories (aka 'blades') you can quickly go from cutting to scraping, to grinding, or to sanding tasks. Unlike other power tools that employ either a circular rotating motion ( hand drills and circ saws) or a reciprocating up-and-down or forwards and backwards motion (jig saws and recip saws), multi-tools employ a side-to-side, arced motion, like a clock pendulum. Typically the range of motion is only a few degrees, but the oscillation is very fast, upwards of 20,000 times per minute. This narrow and fast angle of movement gives you a fairly high degree of tool control.

One of the most common uses of an oscillating tool is flush cutting. Renovators, finish carpenters, flooring and cabinet installers use them for undercutting door casings and jambs; making plunge or pocket cuts into drywall, paneling or flooring without risk of damaging anything behind the cutout; cutting out sections of molding or trimwork without having to remove the entire piece; cutting nails so that trim work can be quickly removed; and, flush trimming copper or plastic piping, screws, and nails.

Bosch recently introduced two corded multi-tools that employ the new Starlock mounting system that was developed jointly by Fein and Bosch. 

The GOP40-30 (which I review here) is classified as their professional tool while the GOP55-36 is geared to the industrial market. The GOP40-30 is available in two kit formats, both of which contain the same multi-tool, but a different set of accessories:

  • GOP40-30C - hard shell case and 6 tools (plus 25 sanding sheets)
  • GOP40-30B - canvas bag and 4 tools (plus 25 sanding sheets).
You don't have much to worry about when it comes to this oscillating tool – after all it's a Bosch tool we're talking about. After 15 years of testing power tools I've yet to encounter a mediocre Bosch. Sure, they aren't perfect – no power tool is. But I have found that with Bosch you get well designed and manufactured tools that offer consistently great durability and performance.

The GOP40-30 features a 4 amp motor that delivers 8,000 to 22,000 strokes per minute in a 3° arc. It has reinforced metal gearing, soft start, and Bosch's 
Constant Response Circuitry – electronic circuitry that maintains constant speed under load so the tool doesn't bog down as it encounters increasing resistance. Plus, it provides electronic overload protection for both the tool and battery – the tool shuts down to prevent the battery from over discharging, or if the battery comes under excessive load or begins to overheat.

No flimsy tool bag here

The GOP40-30C comes in a decent hard shell case that provides better protection for your investment than does the ubiquitous canvas bag. The case also provides ample storage for quite a few accessories – in the supplied accessory storage box, or simply tossed into the case. While I like the case, I would have preferred an L-BOXX, which is stackable. Of course, if you don't have any other Bosch power tools it might be a moot point for you. 

A decent introductory selection of accessories

The kit comes with a useful set of Starlock accessories. The perforated triangular sanding head comes with 25 sanding triangles in 80 and 120 grits. It's unbeatable for just about any kind of detail sanding job, particularly in tight corners, on narrow edges, and in difficult-to-reach areas. Bosch sanding triangles are available in 6 grit sizes from 40 to 240. However, you can use any generic brand.

The 2" curved scraper blade makes short work of removing paint, adhesives, putty, caulking, wallpaper, and other soft materials - in fact anywhere you would normally use a putty knife or paint scraper. The leading edge is ground at a bevel and slightly radiused, while the corners are rounded. This helps to keep the scraper from digging into the work surface. Eventually the leading edge dulls, but you can easily resharpen it on a bench grinder.

The 1/1/4" curved all-purpose bi-metal blade is probably the most commonly used of all oscillating blades. It's suitable for plunge cutting in solid wood and sheet goods, and cutting nails and non-ferrous metals. For any kind of renovation work this is the blade to use. They're also available in other widths up to 2-1/2". It's much more economical to purchase these blades in bulk, especially if you'll be using them frequently. 

While the all-purpose blade does a good job cutting all manner of wood and sheet goods, the 1-1/4" Xtra clean curved wood blade has super sharp teeth that deliver very clean cuts. And, if you're doing a lot of cutting in metal, then the 1-1/4" straight carbide-tipped metal blade is the blade to choose. 

Finally, the GOP40-30C kit comes with a 3-1/2" segment blade doesn't have any set on the teeth, which makes it ideal for flush cutting and straight (rip) cutting, particularly in hard wood, fiberglass, and 20 gauge sheet metal (up to .04"/1mm). And because there is no set on the teeth you can run it along an edge guide to get perfectly straight cuts.

Prices on these new Starlock accessories are comparable to standard blades. Bear in mind that it's the accessory that does the real work on an oscillating tool. No matter how good the tool, a crappy accessory will just give you dismal results. Swiss made Bosch blades are among the best in the business. Our review of Bi-Metal Oscillating Blades rated them top of the crop when it came to cutting life and cost per cut. 

Starlock - the new frontier

Starlock accessories come in three configurations. All feature a 12-point rim star design, but have different center holes, as shown in the illustration above. Accessories with the basic Starlock configuration will fit a majority of the more popular oscillating tools from Bosch, Fein, Makita, and Milwaukee. Accessories with the Starlock Plus or Starlock Max configurations are designed for heavy duty applications, and will work with oscillating tools specifically desinged to accomodate these accessories. Because the GOP40-30 is a Starlock Plus tool, it will accept both the basic Starlock and Starlock Plus accessories.

Check out Fein's compatibility chart to see which oscillating brands and models work with which Starlock configuration.

The various Starlock accessories are colour-coded, making it easier to select the right one – convenient when you have dozens of accessories in your kit.

The amazing Starlock mounting system 

On the GOP40-30 there are two semi-circular, spring loaded tabs, set in a 12-pointed star configuration cup that matches the 12-star configuration on Starlock accessories (top photo above). It looks curiously like a bottle cap. In the middle of the cup are two semi-circular spring-loaded jaws. When an accessory is pressed into the cup (or the cup pushed down onto an accessory), the jaws automatically spread apart to draw the blade into the cup (bottom photo above). The accessory mates perfectly with the tool. 

One of the main advantages of this design is that it increases the contact surface between the accessory and the oscillating tool, which enhances power transmission from tool to accessory. Another advantage is that you don't need to use any tools to install or remove accessories. As anyone who has used an oscillating tool knows, accessories, particularly cutting blades, can get extremely hot in use. 

Flick and fly

To remove the accessory you simply release a lever on the side of the GOP40-30. The spring-loaded jaws retract, and the blade is literally thrown off the end of the housing. The process of removing and mounting an accessory takes just a few seconds. And once an accessory is attached, there is no way it can inadvertently come loose.

My little light's gonna shine

The GOP40-30 has a few other nice features that I like. There's a bright LED light up-front that's useful when working in dimly lit areas such as underneath cabinets, or in crawl spaces.

No-mar plastic ribs

The composite housings used on power tools today are extremely impact resistant. The GOP40-30 is made of glass-filled nylon, know for its strength, stiffness, wear resistance, and dimensional stabilityStill, it can loose its good looks fairly quickly on a jobsite, especially when constantly laid on abrasive surfaces. I like that the sides of the body have plastic strips that provide some protection from scuffs and scratches. 

A little swivel goes a long way

Thankfully, the GOP40-30 doesn't come with the ubiquitous 6-foot power cord found on most corded power tools – this cord is almost 14 feet long. And, it hace a ball-joint that provides the cord an extra bit of give when positioning the tool. 
An indispensible multi-purpose tool

The GOP40-30 performs flawlessly. It's an easy tool to use single-handed, and it has ample power to carry out the sanding, scraping, and cutting jobs it's designed to do. In use there is barely any vibration. However, like all oscillating tools it's very loud, particularly when run at top speed, so hearing protection is required. About the only issue I had with the tool – and a minor gripe at that – was the placement of the variable speed dial at the back of the tool – I would rather have it closer to the power switch.

Whether your a renovator, finish carpenter, or avid DIYer, the Bosch GOP40-30 has all the features you'll need in an oscillating tool, the power to get the job done, and the durability to last.


  • Motor: 4 Amps
  • Size: 2.5" wide by 11" long
  • Material: Aluminum and Glass-Filled Nylon
  • Oscillating Angle: 3.0°
  • Oscillations Per Minute: 8,000-20,000
  • Starlock blade mounting system
  • Constant Response Circuitry
  • Reinforced metal gearing
  • LED work light
  • No-mar plastic ribs
  • Power Cord Length: 13-1/2' with ball-joint swivel 
  • Weight: 3.3lb
  • Includes: 1 each - 1-1/4" Carbide Plunge Blade (OSL114C); 1-1/4" Plunge Blade (OSL114F); 1-1/4" Xtra-Clean Plunge Blade (OSL114JF); 3-1/2" Segment Blade (OSL312F); 2 In. Rigid Scraper Blade (OSL200RS); Sanding Pad; 25 Sanding Sheets; Accessory Box; Carrying Case

MADE IN:Hungary

Carl Duguay
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