BT-JTA Type A Jacobs Taper Arbor

BT-JTA is compact short-neck Type A Jacobs taper conversion tool holder, different from extended BT-JAT. It features integrated short rigid body, one end standard 7:24 BT spindle taper, front Type A JT male taper compatible with all JT1/JT2S/JT3/JT6 key & keyless drill chucks. Short design delivers superior rigidity & less interference, perfect for narrow cavity and small drill tap center high-frequency drilling. Reuse existing workshop Jacobs drill chucks to cut tool procurement cost.

Key Performance Advantages

Compact Short Type A Body, Max Rigidity & Minimal Interference

Shorter distance from flange to Jacobs taper vs BT-JAT, stronger bending resistance, ideal for narrow mold cavities and small drill tap machines. Less vibration under high spindle speed, eliminate wall collision risk.

AT Grade 3 Precision Dual Taper, Runout ≤0.004mm

Mirror ground BT outer taper & Type A Jacobs taper achieve full gap-free contact without offset. Stable radial runout below 0.004mm for smooth hole surface and consistent dimensional accuracy in mass production.

Full JT Size Compatibility For All Drill Chucks

Covers JT1/JT2S/JT3/JT6 standard Jacobs tapers, supports 0.5~16mm full-range drill chucks including micro light chucks & heavy large-bore chucks. Legacy bench & radial drill chucks can be directly mounted on BT machining centers.

One-Piece 42CrMo Alloy Steel, Wear & Impact Resistant

Monolithic 42CrMo alloy steel vacuum carburized to HRC56–62, nitride black anti-rust coating against chip abrasion. Reinforced thick flange resists bending during long high-speed deep hole drilling.

Factory Pre-Balanced G6.3 For Medium-High RPM

All holders dynamically balanced to G6.3 standard, maximum spindle speed up to 15000RPM. Vibration-free for mirror micro-hole finishing on aluminum, stable heavy deep hole drilling on steel & cast iron.

Ultra-Short Standard Lengths For Small Drill Tap Centers

Compact 30/45/60mm total lengths fit BT30 small drill tap machines, BT40 standard vertical mills & BT50 heavy gantry machines, smooth automatic tool change without collision.

Application Industries & Machining Scenarios

• 3C Precision Machining: Mass micro blind hole drilling 0.5~8mm on aluminum housings & graphite jigs
• Mold Manufacturing: Mold base pre-drilling, micro insert positioning holes, narrow cavity cooling holes
• Automotive Components: Tap pilot holes & small step hole mass processing for engine blocks & flanges
• General Machinery: Through & shallow deep hole drilling on steel, cast iron & stainless steel
• Machine Retrofit: Low-cost conversion of existing Jacobs drill chucks to BT machining centers, no full drill holder replacement

Purchase & Selection Guide

• Small drill tap machine & micro 0.5–6.5mm holes: Short 30mm BT30-JTA1
• Universal standard 1–13mm general drilling: BT40-JTA3-45 most versatile
• Large diameter 3–16mm heavy plate drilling: BT40/BT50-JTA6
• Narrow cavity & tight wall limited space: Prioritize 30/45mm short BT-JTA
• Distinction rule: Short compact space choose JTA; long deep cavity interference-free machining select extended JAT