Hitachi

Hitachi 780413 Metal Drill Bit HSS-G 11.5mm

Name: Hitachi 780413 Metal Drill Bit HSS-G 11.5mm
Brand: Hitachi
SKU: 780413

An HSS-G ground-finish bit that drills clean 11.5mm holes through steel and cast iron with a reduced 10mm shank for wider machine compatibility.

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Overview

The Hitachi 780413 is an 11.5mm HSS-G drill bit manufactured to DIN 338 specification — a German standard that defines point angle (118°), helix angle, flute geometry, and dimensional tolerances. The "G" designation means ground finish: the bit's flutes and cutting edges are precision-ground rather than rolled, which produces tighter tolerances and sharper cutting geometry out of the box compared to standard HSS bits. The overall length of 142mm with a 94mm flute length gives this bit the depth capacity to handle most fabrication and repair drilling tasks. The defining feature is the reduced 10mm shank — at 11.5mm cutting diameter, the full shank would normally be 11.5mm, but the reduced shank allows machines with 10mm chuck capacity to run this bit without an adapter.

This bit is aimed at metalworkers, fabricators, and serious DIYers who drill steel regularly and understand the value of ground geometry over commodity bits. It performs best in a drill press or milling machine where spindle speed can be set precisely and feed pressure controlled — optimal speeds for mild steel at this diameter are in the 200–350 RPM range with cutting oil applied at the point. Freehand use in a cordless drill is possible but demands a center punch start and careful technique to avoid walking. The HSS-G material is resharpnable, which matters at this price point — a bit maintained with occasional grinding stays accurate through hundreds of holes. For shops already invested in Hitachi/Hikoki tooling or anyone who needs reliable 11.5mm holes in ferrous and non-ferrous metals, this is a precision consumable that earns its place in the drill index.

Specifications

Diameter

11.5mm

Shank Diameter

10mm (reduced)

Overall Length

142mm

Flute Length

94mm

Material

HSS-G (High Speed Steel, Ground Finish)

Standard

DIN 338

Application

Metal drilling (steel, cast iron, aluminum, brass, hard plastics)

Model

780413

Pros & Cons

👍 Pros

Ground finish (HSS-G) construction produces tighter dimensional accuracy than rolled HSS bits, resulting in cleaner hole geometry closer to the 11.5mm nominal diameter.
Reduced 10mm shank expands compatibility to drill chucks that cannot accept a full 11.5mm shank, without requiring an adapter.
DIN 338 standard geometry ensures a consistent 118-degree point angle that centers reliably when used with a pilot punch.
At 142mm overall length with a 94mm flute, the bit provides sufficient depth capacity for most structural and fabrication drilling tasks without excessive flex.
HSS-G material is resharpnable, making this a cost-effective long-term investment for shops that drill metal regularly.

👎 Cons

The reduced shank-to-diameter ratio means this bit is more susceptible to snap-off under heavy lateral load if the drill wanders — center punching and low feed pressure are non-negotiable.
At 11.5mm, this is a large-diameter HSS bit that requires meaningful torque and low RPM to cut efficiently — it will stall or burn in underpowered handheld drills.
HSS-G lacks the cobalt content of HSS-Co variants, so it dulls faster when drilling hardened or stainless steel; cobalt-grade bits are the better choice for those materials.
No pilot tip geometry — this bit benefits from a pre-drilled pilot hole at smaller diameter for precise positioning in thicker stock.

Frequently Asked Questions

Why does this 11.5mm bit have a reduced 10mm shank, and does that affect performance?

The reduced shank lets this bit fit into drill chucks rated for 10mm maximum capacity — common on smaller bench drills and many cordless hammer drills — without requiring a 12mm or larger chuck. There is a minor trade-off: a reduced shank can introduce very slight runout if the chuck jaws don't clamp squarely, but on a quality drill press with a true chuck this is negligible in practice.

What materials can this bit drill through effectively?

HSS-G (High Speed Steel, ground finish) is rated for steel, cast iron, aluminum, copper, brass, and hard plastics. It is not suitable for masonry, concrete, or hardened tool steel. For structural steel up to around 10mm thickness, this bit performs reliably with proper cutting speed and lubrication.

What drill speed should I use for 11.5mm holes in mild steel?

For mild steel at 11.5mm diameter, a spindle speed of approximately 200–350 RPM is recommended. Running too fast generates excess heat that dulls the cutting edges rapidly. Use cutting oil to reduce friction and extend bit life — this is especially important when drilling through steel plate thicker than 5mm.

Does this bit work in a standard cordless drill, or does it require a drill press?

It fits any drill with a chuck capacity of 10mm or larger. However, for clean, accurate 11.5mm holes in metal, a drill press is strongly preferred — freehand drilling at this diameter risks bit wandering and uneven hole geometry. Use a center punch to establish a pilot point before drilling regardless of which machine you use.

Is this bit rebuildable — can the cutting edges be resharpened?

Yes. HSS-G bits can be resharpened on a bench grinder or with a dedicated drill bit sharpener, restoring the 118-degree point angle to DIN 338 spec. Resharpening is practical for a bit this size and extends useful life considerably compared to disposable carbide bits.