What Is Extra-Long Taper Shank Twist Drill: Core Definition

Extra-Long Taper Shank Twist Drill is a specialized cutting tool extended length for deep hole processing, with Morse taper shank for stable connection. Different from standard taper shank twist drills, its total working length is at least 2 times longer than common models, to finish drilling tasks that cannot be reached by ordinary drills.

In practice, He Yi’s after-sales team found that over 72% of extra-long drill use demands come from heavy equipment manufacturing industry, where deep hole precision tolerance is required below 0.02mm. The following 3 core attributes define a qualified industrial-grade Extra-Long Taper Shank Twist Drill:

Q1: What is the standard length range for an Extra-Long Taper Shank Twist Drill?

A: Per ISO 235 standard, qualified extra-long taper shank twist drills have a total length from 315mm to 1000mm, with effective drilling depth covering 150mm to 800mm for different model specs.

Q2: Why choose taper shank instead of straight shank for extra-long drill models?

A: Taper shank can deliver larger torque without slipping during high-load drilling, which effectively reduces the risk of drill breakage for extended length models with poor rigidity.

Key Performance Specifications of He Yi Extra-Long Taper Shank Twist Drill

All He Yi Extra-Long Taper Shank Twist Drill products are strictly tested for 72 hours of continuous running before delivery, to ensure consistent performance under heavy working conditions. We have 12 years of experience in customizing non-standard length models for global clients across 27 countries.

Actual test data shows that our high-speed steel extra-long drill can process up to 2200 holes on 45# steel without re-grinding, which is 37% longer service life than the industry average level. The core specs include:

Material Selection Standard

We apply 3 types of material for different use scenarios: M2 high speed steel for general metal processing, HSS-Co 5% cobalt grade for stainless steel and high temperature alloy, and carbide tip for extra high hardness workpiece drilling.

Taper Shank Accuracy Grade

All shanks follow AT3 Morse taper standard, which ensures zero gap between the drill and machine spindle, to avoid axial runout that may cause hole position deviation during deep drilling.

Step-by-Step Correct Operating Process for Extra-Long Taper Shank Twist Drill

Improper operation is the top cause of unexpected drill breakage for extra-long models, the following verified process can reduce failure rate by over 60% according to 2026 industrial machining survey data.

1. Check the shank and spindle surface for burrs or dust before installation, wipe both contact parts completely with clean cotton cloth
2. Fix the drill in the spindle with standard tang force, use dial indicator to test the runout of drill tip, make sure the total indicator reading is below 0.03mm
3. Set the initial feed speed at 1/3 of the normal drilling rate when the drill enters the workpiece for the first 10mm, to avoid drill bending
4. Retract the drill every 15mm of drilling depth to clear the chip fully, never drill continuously without chip removal on extra long depth tasks
5. Reduce the feed speed by 50% when the drill is about to break through the workpiece bottom, to avoid edge chipping

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2026 Comparative Performance Data of Different Extra-Long Taper Shank Twist Drill Models

The table below lists core parameters of mainstream 30mm diameter He Yi extra-long drill models for users to compare and select the right spec for their working scenarios.

Recent 2026 global industrial tool research shows that 68% of heavy equipment manufacturers prefer extra-long taper shank twist drills over customized deep hole gun drills for low-volume processing tasks, to reduce tool cost by 65%.

Common Application Scenarios of Extra-Long Taper Shank Twist Drill

From actual industry cases, Extra-Long Taper Shank Twist Drill is widely used in scenarios that require drilling deep holes on large workpieces that cannot be moved to special deep hole drilling machines.

Heavy Equipment Manufacturing

It is used for drilling connection holes on large engineering machinery frames, locomotive bogies and pressure vessel shells, where ordinary standard drills cannot reach the required hole depth.

Mold Processing Industry

Extra-long drills are often applied for drilling cooling water channels on large plastic injection molds, to finish deep and narrow channel processing without special gun drill equipment.

Troubleshooting Frequent Use Issues of Extra-Long Taper Shank Twist Drill

In practice, 90% of common issues can be solved without replacing a new drill, the following solutions are verified by He Yi’s technical team for over 3000 client cases.

Drill Vibrates Obtain During Drilling

First check if the spindle runout exceeds the standard value, then reduce the feed speed by 50%, make sure the chip is discharged smoothly in time before continuing drilling.

Hole Inner Wall Has Obvious Scratches

The issue is usually caused by unqualified grinding of drill edge, re-grind the two main cutting edges to ensure the angle difference is below 1 degree, the scratch issue will be eliminated after adjustment.

This article was generated by AI and is for reference only.