29Pcs Cobalt Drill Bit Set, 135 Degree Tip High Speed Steel with Black and Gold Finish, Stainless Steel, Plastic, and Wood with Metal Indexed Storage Case 1/16"-1/2"

I used these bits to predrill holes for deck railing fasteners. Worked great.

great product used a few times there great

They perform great for inexpensive bits.

Based on the price ($34.99) at time of review, the YOHANSEN-USA Drill Bit Set is a solid deal. In my limited tests using wood and aluminum, the bits performed well. My only issue with the set is the included case. The case may be made of metal, but it can be difficult to open. In addition, the printed sizes are difficult/impossible to read on larger bits due to the fact the trays do not separate/fold down. I moved the entire set of bits into a Drill America Drill Bit Index/Case which is easier to open and has easy fold down separators. 4/5

some say it's cobalt some say it's not and all "cobalt" bits are is 5% or 7% cobalt added to high speed steel. But the insert shows it's good for "steel wood & plastic" and mention nothing about stainless or cast so that might be a hint. regardless and I haven't even used them yet, even if it is just regular high speed steel you're not gonna beat this value for around 80 bucks A lot of people complaining about breakage I don't know what to tell you. The better the drill bit the more brittle it will be and if you really wanna get max effectiveness take a couple minutes to talk to a robot about cutting speed although it may works most of the time for you, it really shouldn't just be chuking up any size drill bit to drill any type material with your finger all the way on the trigger - some materials are picky & require greater attention to detail like stainless is one of the hardest to drill but you just need a steady feed but not a lot of speed you gotta make sure you're making chips and not just rubbing sticks otherwise you're just melting the end of the bit and work hardening the stainless anyway, I'm gonna highly recommend them even before use just from inspection and general common sense - I mean if you're not a machinist it's essentially three sets of bits because a DIY guy slapping a bracket on a bunkbed or something might not give a crap between an A (0.234) a number 1 (0.228) or a quarter inch (0.250) somebody mentioned they got extra bits, I didn't get extra bits somebody mentioned the case is real flimsy, well it's just as flimsy and cheesy as they've always been as far as I'm concerned happy drilling

Though these are nice drill bits, they are not M35 cobalt HSS drill bits. The box and the drill bits themselves do not show any indication of being cobalt but only HSS and titanium coated. Reading further down in the 'Product Description' of the Amazon item page, it states these are "Made from high-speed steel and coated with cobalt" and not M35 cobalt HSS. The 'About this item' section is misleading for the '21pcs Cobalt Mini' item indicating they are M35 cobalt; this needs to be changed.

Mildly surprised by their performance. Working on drilling holes in A33 tool steel. I was able to drill 63 through holes an inch and a half thick . Start to finish they drilled true, even without using a spotting drill prior to drilling. Very minimal deflection on the other side of the material, minimal residual burrs on exit. Very satisfied on the cost/performance. Pictures show hole drilling performance on the last blank, starting a hole and then top and bottom of blank showing minimal burr formation. 200rpm heavy feed by hand, little bit of lubrication using a mixture of cutting oil and turpentine. There’s a a picture of drill bit after completion of the holes, and a comparison of old and new together. Good bang for the buck!

What a full set of quality drill bits. I'm very impressed with this set and definitely intend on being a repeat client. Highly recommend this company.