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MINIATURE STRAIGHT SHANK DRILL BIT

Home> Miniature Straight Shank Drill Bit
Home > Miniature Straight Shank Drill Bit

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Micro Drill Bits #53–#97 & 1/64
Micro Drill Bits #53–#97 & 1/64
Micro Drill Bits #53–#97 & 1/64
Micro Drill Bits #53–#97 & 1/64
Micro Drill Bits #53–#97 & 1/64
Micro Drill Bits #53–#97 & 1/64

Micro Drill Bits #53–#97 & 1/64"–3/64" — HSS M2 / M35 / M42, 118° Point, ANSI Standard

Number drills #53–#97 (1.511–0.150 mm) and fractional micro drill bits 1/64"–3/64" in HSS M2, M35 (5% Co) and M42 (8% Co). 118° conical point, straight shank, ANSI/ASA B94.11M nominal sizes, bright or black oxide finish. MOQ 500 pcs per size.

Brand:
AMSUO
Spu:
AMS-MICRO-ND53-97
Inquiry
  • Overview
  • Specifications
  • Recommended Products

When a hole gets below one millimetre, the drill stops being a disposable consumable and starts being a precision component. This range covers the smallest sizes we make on a production basis — number drills #53 down to #97 and fractional sizes 1/64" to 3/64" — in HSS M2, M35 and M42, ground to US (ANSI/ASA B94.11M) nominal sizes with a 118° point and straight shank. Every size is stocked as a standard catalogue item, not a special order.

Diameter range
0.150 – 1.511 mm
#97 to #53 wire gauge
Materials
M2 / M35 / M42
0% · 5% · 8% cobalt
Point geometry
118°
135° split point optional
Minimum order
500 pcs
per size, mixed sizes allowed

What this range is built for

Micro drilling fails for one of three reasons: the bit is eccentric to the spindle, the chip cannot get out, or the tool is too soft for the material. This range is specified to remove all three variables from the tool side of that equation.

Concentric grinding

Point and flutes are ground between centres in one operation, so runout at the point stays inside the tight window these diameters demand. A 0.4 mm bit with 0.02 mm runout is already cutting oversize.

Polished flutes

Bright-finish flutes reduce friction and chip adhesion at low chip loads. Available in black oxide where you need lubricant retention and better chip flow on gummy materials.

Cobalt where it matters

M35 (5% Co) and M42 (8% Co) hold hardness at the temperatures microdrilling generates. On stainless and titanium, that is the difference between one hole and forty.

How small is small

At the bottom of this range the tool is thinner than a human hair. The chart below is drawn to true relative scale against a 0.07 mm hair, so you can judge what you are ordering before you order it.

Human hair
0.070 mm
#97 micro drill
0.150 mm
#79 micro drill
0.368 mm
1/64" drill
0.397 mm
#53 drill
1.511 mm

Bars scaled to the largest size in the range (#53, 1.511 mm = 100%). The three photographs below show 1/64" and #79 bits against a ballpoint pen for a physical reference.

1/64 inch and #79 HSS micro drill bits beside a ballpoint pen for scale Bulk pack of 1/64 inch HSS micro drill bits, 0.397 mm diameter Size comparison of #79 micro drill bits and 1/64 inch drill bits in vials

M2, M35 or M42 — choosing the grade

All three grades share the same geometry and the same nominal sizes. The difference is cobalt content and the hot hardness it buys you.

Grade Cobalt Typical hardness Best for Trade-off
M2 0% 63–65 HRC Aluminium, brass, copper, plastics, wood, mild steel — the general-purpose choice and the most economical per hole Loses hardness quickly in stainless and high-alloy steel
M35 5% 64–66 HRC Stainless steel 304/316, alloy steel, high-tensile fasteners, production runs where tool changes cost more than the bit More brittle than M2 — punish it with runout and it snaps
M42 8% 65–67 HRC Titanium alloys, Inconel and nickel-based alloys, hardened tool steel, abrasive composites Highest cost per piece; demands rigid, high-speed spindles

Hardness figures are typical values after full heat treatment and apply to the shank body; they are reference values, not acceptance criteria for a specific lot. Tell us the workpiece material and we will recommend the grade and the geometry.

Fractional sizes — 1/64" to 3/64"

Three fractional diameters, each in a standard and a B-series length. The B series extends overall length, which buys you reach in deep cavities and fixture plates.

Stock No. Size Ø mm Ø inch OAL mm Flute mm OAL inch Flute inch Series
J150097 1/64" 0.397 0.0156 19.05 4.76 0.75 0.1874 Std
J150098 1/32" 0.794 0.0313 34.925 12.7 1.375 0.5 Std
J150099 3/64" 1.191 0.0469 44.45 19.05 1.75 0.75 Std
J150097B 1/64" 0.397 0.0156 28.6 4.76 1.126 0.1874 B
J150098B 1/32" 0.794 0.0313 28.6 12.7 1.126 0.5 B
J150099B 3/64" 1.191 0.0469 38.1 19.05 1.5 0.75 B

Dimensions in millimetres per the quoting sheet; inch values converted at 25.4 mm. Stock numbers ending in "B" are a separate production series — overall length differs where shown. Quote by stock number.

Number sizes — #53 to #97

The full wire-gauge run from #53 (1.511 mm) to #97 (0.150 mm). Sizes #61 and finer are produced in the B series; #53 to #60 are available in both series.

Stock No. Size Ø mm Ø inch OAL mm Flute mm OAL inch Flute inch Series
J160153 53 1.511 0.0595 47.62 22.225 1.8748 0.875 Std / B
J160154 54 1.397 0.0550 47.62 22.225 1.8748 0.875 Std / B
J160155 55 1.321 0.0520 47.62 22.225 1.8748 0.875 Std / B
J160156 56 1.181 0.0465 44.45 19.05 1.75 0.75 Std / B
J160157 57 1.092 0.0430 44.45 19.05 1.75 0.75 Std / B
J160158 58 1.067 0.0420 41.275 17.4625 1.625 0.6875 Std / B
J160159 59 1.041 0.0410 41.275 17.4625 1.625 0.6875 Std / B
J160160 60 1.016 0.0400 41.275 17.4625 1.625 0.6875 Std / B
J160161B 61 1 0.0394 41.275 17.4625 1.625 0.6875 B
J160162B 62 0.973 0.0383 38.1 15.875 1.5 0.625 B
J160163B 63 0.94 0.0370 38.1 15.875 1.5 0.625 B
J160164B 64 0.914 0.0360 38.1 15.875 1.5 0.625 B
J160165B 65 0.889 0.0350 38.1 15.875 1.5 0.625 B
J160166B 66 0.838 0.0330 34.925 12.7 1.375 0.5 B
J160167B 67 0.813 0.0320 34.925 12.7 1.375 0.5 B
J160168B 68 0.787 0.0310 34.925 12.7 1.375 0.5 B
J160169B 69 0.742 0.0292 34.925 12.7 1.375 0.5 B
J160170B 70 0.711 0.0280 31.75 9.525 1.25 0.375 B
J160171B 71 0.66 0.0260 31.75 9.525 1.25 0.375 B
J160172B 72 0.635 0.0250 31.75 9.525 1.25 0.375 B
J160173B 73 0.61 0.0240 31.75 9.525 1.25 0.375 B
J160174B 74 0.572 0.0225 25.4 6.35 1 0.25 B
J160175B 75 0.533 0.0210 25.4 6.35 1 0.25 B
J160176B 76 0.508 0.0200 22.225 4.7625 0.875 0.1875 B
J160177B 77 0.457 0.0180 22.225 4.7625 0.875 0.1875 B
J160178B 78 0.406 0.0160 22.225 4.7625 0.875 0.1875 B
J160179B 79 0.368 0.0145 19.05 3.175 0.75 0.125 B
J160180B 80 0.343 0.0135 19.05 3.175 0.75 0.125 B
J160181B 81 0.33 0.0130 19.05 2.381 0.75 0.0937 B
J160182B 82 0.318 0.0125 19.05 2.381 0.75 0.0937 B
J160183B 83 0.305 0.0120 19.05 2.381 0.75 0.0937 B
J160184B 84 0.292 0.0115 19.05 2.381 0.75 0.0937 B
J160185B 85 0.279 0.0110 19.05 2.381 0.75 0.0937 B
J160186B 86 0.267 0.0105 19.05 2.381 0.75 0.0937 B
J160187B 87 0.254 0.0100 19.05 1.984 0.75 0.0781 B
J160188B 88 0.241 0.0095 19.05 1.984 0.75 0.0781 B
J160189B 89 0.231 0.0091 19.05 1.984 0.75 0.0781 B
J160190B 90 0.221 0.0087 19.05 1.984 0.75 0.0781 B
J160191B 91 0.211 0.0083 19.05 1.984 0.75 0.0781 B
J160192B 92 0.201 0.0079 19.05 1.588 0.75 0.0625 B
J160193B 93 0.191 0.0075 19.05 1.588 0.75 0.0625 B
J160194B 94 0.18 0.0071 19.05 1.588 0.75 0.0625 B
J160195B 95 0.17 0.0067 19.05 1.588 0.75 0.0625 B
J160196B 96 0.16 0.0063 19.05 1.588 0.75 0.0625 B
J160197B 97 0.15 0.0059 19.05 1.588 0.75 0.0625 B
Note on the finest sizes: #91, #92, #93, #94, #95, #96, #97 (0.150–0.211 mm) are outside our standing stock programme and are made to order. Lead time applies — contact us with your annual quantity and we will confirm tooling and schedule.

Starting parameters

Micro bits break from wrong parameters far more often than from bad steel. These are conservative starting points for HSS micro drills — run a test hole, then adjust.

Workpiece Cutting speed Vc (m/min) Feed per revolution Coolant
Aluminium 60–100 0.02–0.04 mm/rev Kerosene or soluble oil, flood
Brass / copper 50–80 0.02–0.04 mm/rev Soluble oil
Mild / carbon steel 25–35 0.01–0.03 mm/rev Flood, 8–10% concentration
Alloy steel 18–25 0.01–0.02 mm/rev Flood, high pressure
Stainless 304/316 12–18 0.01–0.02 mm/rev Flood, never run dry
Titanium 8–12 0.008–0.015 mm/rev High-pressure flood, sharp and copious
Hardened steel ≤ 45 HRC 8–12 0.008–0.015 mm/rev Flood — M42 only

Spindle speed follows from diameter: n (rpm) = 1000 × Vc ÷ (π × D). A 0.4 mm bit at 30 m/min needs roughly 24,000 rpm — below that you are rubbing, not cutting. Peck in increments of 0.5–1× diameter, keep total runout under 0.01 mm, and hold the bit in a precision collet, never a three-jaw chuck.

Where they are used

PCB & electronicsVia holes, pin holes and component lead clearance in FR4 and phenolic board.
Jewellery & watchmakingPilot holes for settings, hinge pins and bracelet links in precious and base metals.
Injection nozzlesOrifice drilling in brass and stainless nozzle tips, where hole size sets flow rate.
Model & instrument makingFine mechanical assemblies, gauge bodies, camera and optical hardware.
Aerospace fastenersLockwire holes, rivet pilots and EDM start holes in high-temp alloys.
Dental & medicalInstrument repair, bur blanks and precision component work.

Finish, packing and OEM options

Surface finish Bright (polished) or black oxide, as standard. TiN and TiAlN coatings available on request for extended life in abrasive materials.
Point geometry 118° conical point as standard. 135° split point available for hard materials and for reduced walking on curved surfaces.
Packing Bulk bag (500 pcs), plastic vial (10 or 100 pcs), or indexed case sets. Tell us the format your shelf and your customers expect.
Branding Laser marking on shank where diameter allows, printed vials, colour-coded caps, private-label artwork and barcoded labels.
Documentation Dimensional inspection data, material certificates and lot traceability available with your order on request.

Questions buyers ask

What is the difference between a number drill and a fractional drill?
Number drills are identified by wire-gauge number (#1 to #80) and step in very fine increments, which is why they are used where a hole must match a specific pin, wire or tap drill size. Fractional drills are identified by inch fraction. Both are defined nominally under ANSI/ASA B94.11M; a #53 is 1.511 mm and a 1/64" is 0.397 mm, so the two series interleave rather than replace each other.
Do you supply the finest sizes, #91 to #97?
They are made to order rather than held in stock. Send us the size list and annual volume and we will confirm tooling, lead time and price. See the note under the number size table.
Can I mix sizes in one order?
Yes. Minimum order quantity is 500 pcs per size, and sizes can be combined within a single order and a single shipment. Mixed-size sets in indexed cases are also available.
Are M35 and M42 available in these diameters?
Yes — the range is produced in M2, M35 (5% Co) and M42 (8% Co) to the same nominal sizes and geometry. Cobalt grades carry a price premium and, on the finest sizes, a longer lead time.
Can I get samples before placing a bulk order?
Sample quantities of catalogue sizes are available for evaluation. Tell us the workpiece material and the machine you will run them on, and we will send the grade and geometry that suit it.
What is the diameter tolerance?
Sizes are ground to ANSI/ASA B94.11M nominal. If your application needs a tightened or unilateral tolerance band, state it on the enquiry — on micro diameters the tolerance is as much a process decision as the size itself.
Request a quotation
Send us your size list — we will quote by stock number, grade and quantity.

Sizes #53–#97 and 1/64"–3/64", M2 / M35 / M42, bright or black oxide, bulk or private label. Volume pricing from 500 pcs per size.

Contact our sales team
Material HSS M2 / M35 (5% Co) / M42 (8% Co)
Standard ANSI/ASA B94.11M (US standard), nominal sizes
Size Range #53–#97 (1.511–0.150 mm) and 1/64"–3/64" (0.397–1.191 mm)
Number of Sizes 45 wire-gauge + 3 fractional, in standard and B length series
Point Angle 118° conical (135° split point on request)
Flute 2-flute, right-hand cutting, standard helix
Shank Straight (miniature straight shank)
Finish Bright or black oxide
Overall Length 19.05–47.62 mm, by size
Minimum Order 500 pcs per size, sizes may be combined
Packing Bulk bag / plastic vial / indexed case
Application PCB, jewellery & watchmaking, nozzle orifices, model making, aerospace fasteners

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