Which Cutting Oil Brand Wins?
In our test we compared 10 cutting oil options head to head. Tap Magic EP Extra Cutting Fluid came out on top. See the measured results, the runner-up, the budget pick, and a link to the full test video.
Tap Magic EP Extra Cutting Fluid
Price shown in test: $14.28
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CRC C3400 Truetap
Price shown in test: $13.75
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The quick take
The short version of why each pick lands where it does, built straight from the measured results.
“Tap Magic seems to have come out on top with CRC in a very close second. I was also really impressed with CLI Syntec as well as Rapid Tap.”
Best in 1 of 2 measurements, including Mild Steel Drill Time.
The measured results
Every number below is read straight from the test. Products are listed in the order they finished.
Lubricity Wear Scar
- 1Tap Magic EP Extra Cutting Fluid
slightly lower viscosity than CRC, about the same as Lenox; wear scar incredibly small, possibly smaller than CRC's
- 2CRC C3400 Truetap (CRC True Tap HD Cutting Fluid)
higher viscosity than Lenox and 3-in-1 oil, clung well to the wheel; tiny wear scar, much better than Lenox and 3-in-1
- 3CLI Syntec Premium Metal Tapping Fluid
slightly higher viscosity than Tap Magic and Oatey, close to CRC; smallest wear scar of all products tested on the lubricity tester
- 4Rapid Tap heavy-duty cutting fluid (manufactured by Relton Corporation)
about the same viscosity as CRC, clung well to the wheel; smallest wear scar yet at the time it was tested
- 5Oatey Clear Thread Cutting Oil
slightly lower viscosity than Tap Magic; wear scar impressive but not quite as good as CRC or Tap Magic
- 6Shortening vegetable shortening (prepared from meat fats and vegetable oils, gluten-free)
highest viscosity of all products tested; lots of metal-on-metal contact, warmed up quickly; one of the largest wear scars of all products
- 7Bacon grease
warmed up quickly, decent cling to the wheel, but more metal-on-metal contact than the top cutting oils; smelled the best of all products tested
- 8used motor oil from the narrator's Dodge 2500 diesel engine
viscosity about the same as CRC and CLI Syntec, clung well to the wheel, but more metal-on-metal contact than the top oils per the energy-use analyzer
- 93-in-1 Oil 3-in-1 multi-purpose oil
lowest viscosity of all products compared at that point; pretty big wear scar, evaporated faster than Lenox
- 10Lenox Pro Tool Lube
pretty big wear scar, described as not having very good film strength
Mild Steel Drill Time
- 1Tap Magic EP Extra Cutting Fluid31 seconds
tied with Oatey for the best time of all 9 real products (versus 79 seconds for the no-oil control)
- 2CRC C3400 Truetap (CRC True Tap HD Cutting Fluid)35 seconds
took the lead from 3-in-1 oil at the time but later matched by CLI Syntec and Rapid Tap
- 3CLI Syntec Premium Metal Tapping Fluid35 seconds
- 4Rapid Tap heavy-duty cutting fluid (manufactured by Relton Corporation)35 seconds
- 5Oatey Clear Thread Cutting Oil31 seconds
tied with Tap Magic for the best time of all 9 real products
- 6Shortening vegetable shortening (prepared from meat fats and vegetable oils, gluten-free)47 seconds
- 7Bacon grease45 seconds
better than shortening but not as good as most of the purpose-made cutting oils
- 8used motor oil from the narrator's Dodge 2500 diesel engine55 seconds
worse than every purpose-made cutting oil and worse than Lenox (40s) and 3-in-1 (37s), better only than the 79-second no-oil control
- 93-in-1 Oil 3-in-1 multi-purpose oil37 seconds
3 seconds faster than Lenox despite the poor film strength
- 10Lenox Pro Tool Lube40 seconds
Armor Plating Test
- 1Tap Magic EP Extra Cutting Fluid
cut all the way through in 48 seconds, taking the lead from CRC; small chip in the leading edge but chisel in great shape
- 2CRC C3400 Truetap (CRC True Tap HD Cutting Fluid)
cut all the way through in 50 seconds, got stuck at final breakthrough; chip in leading edge likely from breakthrough, otherwise in much better condition than the first three drills tested
- 3CLI Syntec Premium Metal Tapping Fluid
made it through the armor plating in 65 seconds, one of only three products (with CRC and Tap Magic) to fully break through the armor plating in that portion of the recap; large chip in the leading edge of the chisel but most of the leading edge still in good condition
- 4Rapid Tap heavy-duty cutting fluid (manufactured by Relton Corporation)
drill bit tip made it all the way through the armor plating but could not fully break through, stopping around 50 seconds; small chip in leading edge, overall very good condition with minor wear to the chisel
- 5Oatey Clear Thread Cutting Oil
stopped making progress after about 20 seconds, did not fully break through; narrator states it did better than the control, Lenox, and 3-in-1 oil but not as good as CRC or Tap Magic; quite a bit of damage to the leading edge and a pretty worn chisel
- 6Shortening vegetable shortening (prepared from meat fats and vegetable oils, gluten-free)about40 seconds
of cutting action before stopping, did not fully break through; several chips in the leading edge and wear to the chisel. The closing recap states shortening did slightly better than bacon grease on this test
- 7Bacon grease
did not fully break through, reaching about 3/4 of the way through the armor plating; small chip in leading edge and quite a bit of wear to the chisel
- 93-in-1 Oil 3-in-1 multi-purpose oil
less smoke than Lenox but still no match for the armor plating; lots of damage to the leading edge and chisel after 22 seconds, did not break through
- 10Lenox Pro Tool Lube
twist drill almost immediately went up in smoke; badly damaged after 20 seconds, did not break through
- 8used motor oil from the narrator's Dodge 2500 diesel enginenot tested
How it was tested
- lubricity/film-strength test (40ml oil, 30 second run, bearing wear-scar size comparison)
- mild steel drilling speed test (3/8in twist drill, 1/2in mild steel, 600 RPM, about 121 lb downward force, seconds to break through)
- armor plating drilling test (3/8in split-point drill, 3/8in armor plating, 340 RPM, about 250 lb downward force, seconds and/or breakthrough outcome)
“Tap Magic seems to have come out on top with CRC in a very close second. I was also really impressed with CLI Syntec as well as Rapid Tap.”
Data notes and caveats
The video description's Products Tested list (both the prose sentence and the implicit product set) names 9 items but omits Oatey Clear Thread Cutting Oil, which the transcript introduces by name and price ($15.95) and tests fully and consistently through both the mild-steel and armor-plating segments, tying Tap Magic for the fastest mild-steel time; it is included here as a genuine tenth product per the rule that a consistently-tested transcript brand is real even if the description omits it. The no-cutting-oil control run (79 seconds mild steel, about 3 seconds on armor plating) is a baseline, not a competing product, and is excluded from products[] but its numbers are referenced in several products' notes for context. Used motor oil was explicitly excluded from the armor-plating round on camera (only 10 new drills available, and it had already finished second-to-last on the mild-steel speed test), not lost to a caption gap. Two brand names are auto-caption mangles resolved via the description and product-category plausibility: 'Lennox'/'Linux' resolves to Lenox, and the recap's one-off 'Peking Grease' resolves to Bacon Grease. products[] is ordered by the closing verdict's explicit ranking (Tap Magic winner, CRC close second, CLI Syntec and Rapid Tap both praised by name) followed by the remaining six products ordered by armor-plating performance (the harder, more decisive test), since no single test ranks all ten products against each other in one event.
