Answering the question of which 7/8 inch step drill bit to choose, this guide highlights five solid options that cover metalworking, DIY metal, plastic, and wood applications. These picks suit different buyers: professionals needing durability, hobbyists seeking smoother cuts, and casual users who want fast hole expansion. Read on to compare features, materials, and performance notes to decide which unibit best fits your needs.
| Product | Best For |
|---|---|
| toolant Four Spiral Flute Cobalt Step Drill Bit (12 steps) | Durable steel cutting with high-speed metal working |
| Jerax tools M2 HSS Quick Change Step Drill Bit (3/16–7/8″) | Impact-ready drilling with quick bit changes |
| NEIKO 10185A Titanium Step Drill Bit | Clean holes across metal and wood with deburring |
| Jerax tools HSS 1/4–7/8 Inch Step Drill Bits | Versatile non-stop drilling across metals and plastics |
| Klein Tools QRST11 Step Drill Bit | Impact-rated, durable coating for long life |
toolant Four Spiral Flute Cobalt Step Drill Bit
The toolant bit uses four spiral flutes to speed cutting and provide a smoother hole for metal and plastics. A TiAlN coating increases surface hardness, enabling faster cutting speeds on harder materials, and the M35 cobalt steel core boosts durability for repeated use. This unibit covers 1/4″ shank compatibility and a size range from 3/16″ to 7/8″.
Best for: Metalworkers and fabricators who need robust performance with smoother chip evacuation. Better for users who frequently work with stainless steel, aluminum, and copper sheets. A potential limitation: data notes only a 12-step range; users needing larger increments may want alternatives with more steps.
Jerax tools M2 HSS Quick Change Step Drill Bit
This double-fluted, M2 HSS bit emphasizes clean holes and faster drilling, aided by tungsten and molybdenum enrichment for durability. Quick-change 1/4″ hex shank enables rapid bit swaps on impact drivers. The design includes non-stop size visibility—read the target size without stopping to measure.
Best for: Professionals seeking quick changes and consistently clean holes in stainless steel, copper, and aluminum. Caution: the data suggests high performance; users with lighter tools should verify if impact-rated tools are compatible with their setup.
NEIKO 10185A Titanium Step Drill Bit
NEIKO’s unibit is built from #4241 industrial HSS with a titanium nitride coating for durability. It features a 135-degree split-point tip to start cutting quickly and a two-fluted spiral design to deburr and expand holes as you drill. The straight design helps reduce chatter for smoother operation across metal, wood, copper, and plastics.
Best for: Users needing a reliable, all-around metal and wood hole expander that reduces chatter and deburring. Limitation: while versatile, the 10-step range may be less granular than 12-step sets for some projects.
Jerax tools 3/16 to 7/8 Inch Step Drill Bit
This straight-grooved, double-fluted M2 HSS bit emphasizes non-stop size visibility during drilling. It uses vacuum heat treatment and nitride surface hardening to enhance durability and precision. The kit includes steps from 3/16″ to 7/8″, designed for metal and plastic drilling with a quick-change feature for fast bit swaps.
Best for: Metal and plastic hobbyists who value quick visibility of the target size and fast, clean holes. Use caution: ensure your drill and driver are compatible with double-fluted step bits to avoid binding.
Cobalt M35 Step Drill Bit 3/16″ to 7/8″
This drill bit uses M35 cobalt steel and TiAlN coating, delivering superior durability for stainless steel, metals, and plastics. The 4-spiral-flute design promotes fast cutting and efficient chip removal, while the 118° split-point tip helps with self-centering and faster start.
Best for: Professionals needing enhanced toughness on stainless steel; avoid this if your project involves very soft materials where cutting speed is a lower priority than surface finish.
Saiper Titanium Step Drill Bit (12 Step Sizes)
Saiper’s bit uses titanium-coated HSS to deliver smoother cutting and faster chip removal with 12 step sizes, including 3/16″ up to 7/8″. The two-flute design supports efficient debris clearing, making it easier to complete holes in a single pass across plastics and metals alike.
Best for: DIYers needing a broad size range in a single bit set and a smoother cut. Limitation: multi-size bits can be heavier; ensure your drill can handle the weight for extended use.
Buying Guide: Key Considerations For 7/8 Inch Step Bits
Material compatibility
Consider whether you will drill metal, stainless steel, aluminum, copper, wood, or plastic. Bits with cobalt (M35) or HSS with TiAlN coatings are best for metal and stainless steel, while high-speed steel variants work well for softer materials.
Coatings and durability
Coatings such as TiAlN increase hardness and reduce wear, extending life in tough materials. For long-term use, coatings that resist heat build-up help maintain cutting speed and edge sharpness.
Flute design and chip removal
4-flute or 2-flute designs influence cutting speed and debris clearance. More flutes can cut faster but may require careful control to prevent chatter. Dual-flute designs often offer smoother operation and easier chip removal.
Hole size range and step count
12-step sets provide finer control across the range, while fewer steps might be adequate for straightforward tasks. Verify the smallest and largest holes you need before purchasing.
Shank type and compatibility
Most 7/8″ step bits use a 1/4″ hex shank for impact drivers and standard drills. Ensure your tool accepts hex shanks and, if using impact tools, confirm impact-rated compatibility.
Ease of use and visibility
Some bits feature clear size highlights or quick-change shanks to speed workflow. Quick-change bits are particularly useful in professional settings where time matters.
Limitations to consider
- Very hard metals may require cobalt or TiAlN-coated bits; uncoated bits may wear quickly on stainless steel.
- Higher-step counts can add weight and price; assess whether you need every size in the set.
- Some designs emphasize deburring; if that isn’t necessary, you might favor other features like speed or precision.
Frequently Asked Questions
- What is a step drill bit used for?
Step drill bits widen holes progressively and deburr as they drill, making them ideal for electrical boxes, pipe fittings, and sheet metal work.
- Which material is best for 7/8″ step bits?
High-speed steel with coatings (like TiAlN) or cobalt-based HSS perform best on metal, especially stainless steel, aluminum, and copper.
- Do I need an impact-rated drill for these bits?
Impact-rated tools can improve performance with impact drivers, but many 7/8″ step bits also work in standard drills. Check your tool’s chuck compatibility.
- How many holes can I drill before sharpening?
This depends on material hardness and tool quality. Coated and cobalt bits typically require fewer sharpenings for metal work than standard HSS.
- Are spiral flutes better than straight flutes?
Spiral flutes generally cut faster and remove chips efficiently, while straight flutes can offer steadier cuts in softer materials.