GSTIN: 29AAHCH5227L1Z6
•ISO 9001:2015
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ER Collets
ER-8 Spring Collet — 0.5→5mm Range
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ER-8 Spring Collet — 0.5→5mm Range—
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ER-8 Spring Collet — ISO 15488 / DIN 6499 (8°)
Universal, high-grip tool holding for mills, lathes, routers & grinders. ER-8 collets follow the ISO 15488 / DIN 6499 standard (8°) and are compatible with any ER-8 chuck.
Choose your accuracy
- Standard (≤15 µm TIR) — dependable everyday accuracy.
- High-Precision (≤8 µm TIR) — tighter runout for better finish & tool life.
- Ultra-Precision (≤5 µm TIR) — finishing-grade concentricity; also available as sealed coolant collets in this grade.
Optional: With matched premium holders (e.g., balanced G2.5), system runout can reach ≤3 µm.
Pick your inner hole size (ID)
Metric IDs from 0.5 mm → 5 mm in 1 mm steps (and 0.5 mm half-steps). Each ER-8 collet normally collapses ~1 mm (e.g., 6.0 grips 6.0→5.0 mm). Very small IDs (≈≤3 mm) have a reduced collapse (~0.38 mm).
Quick size guide (examples)
- 0.5–3 mm: PCB tools / micro-drills (reduced collapse).
- 4–8 mm: General drilling, light milling.
- 5 mm: Larger drills/end mills within ER-8 envelope; verify tool shank tolerance (h6/H6) for best grip.
Choosing your size (step-by-step)
- Measure the shank (e.g., Ø 6.0 mm h6).
- Pick the collet nominal ≥ shank—never clamp above nominal.
- Prefer the closest nominal (e.g., 6.0 for a 6.0 mm shank; not 7.0).
- Decide type:
- Standard (vented) → 1.0 mm collapse (better range).
- Sealed (coolant-through) → 0.5 mm collapse (keeps chips/coolant out).
- Pick accuracy: ≤15 µm TIR, ≤8 µm TIR, ≤5 µm TIR (collet-only, at bore, 20 °C).
Why machinists choose ER-8
- Wide clamping range, fewer changeovers. Each ER collet provides ~1 mm collapse (commonly 1 mm steps across a set), so a 6 mm ER-8 collet securely clamps 6.0 → 5.0 mm. This minimizes inventory and speeds setups.
- Proven accuracy. Quality ER collets hold ≤15 µm TIR / ≤8 µm TIR / ≤5 µm TIR (collet-only TIR), boosting tool life and surface finish.
- Built for performance. Made from hardened spring steel and precision-ground for repeatable concentricity and grip.
- Coolant-through options. Sealed ER-8 collets support through-tool coolant—many rated to ~2000 psi (138 bar).
- Universal compatibility. Fits any ER-8 collet chuck (BT, CAT, HSK, straight-shank, etc.); use with UM/Hex/Mini nuts (standard M10×1.0 thread for ER-8).
Key specifications (ER-8)
- Standard: ISO 15488 / DIN 6499 (ER system, 8° taper)
- Clamping range: ~1 mm (per collet), sets typically in 1 mm steps
- Accuracy grades:
- Standard: ≤15 µm TIR (collet-only)
- High Precision: ≤8 µm TIR (collet-only)
- Ultra Precision: ≤5 µm TIR (collet-only)
- Shank tolerance: h6/H6 recommended for best performance
- Nut interface: UM/Hex/Mini; M10×1.0 (std. ER-8 nut thread)
- Coolant: Open (standard) or sealed (coolant-through) options available; sealed types often rated to ~2000 psi
Tip on torque: Typical recommended tightening torque for ER-8 nuts ranges 10–20 Nm, varying by nut style (castle/slotted/hex) and tool diameter—always follow your nut/chuck maker's table.
Coolant-through options
Select Sealed (coolant-through) ER-8 collets to deliver pressure to the tool tip; many are rated up to ~2000 psi. Use on-size sealed collets (no collapse) for proper sealing.
What it's great for
- High-mix machining where fast tool swaps and wide coverage matter
- End mills, drills, reamers, routers (round shanks) in the 0.5–5 mm range (typical ER-8 set coverage)
- Applications needing coolant-through clamping (sealed ER-8)
How to install (for best TIR)
- Snap the collet into the nut first (engage the extractor ring)
- thread onto the chuck
- insert clean on-size shank
- tighten with a torque wrench to your nut/chuck table. Never tighten an empty collet. (Follow your holder's torque chart.) (Standards & maker docs reference this method to preserve runout.)
Available nominal sizes (ER-8)
0.5 → 5 mm (whole & half-steps) 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5
Clamp bands (examples) • Standard 6.0 → clamps 6.0 → 5.0 mm • Standard 6.5 → 6.5 → 5.5 mm • Sealed 6.0 → 6.0 → 5.5 mm • Sealed 6.5 → 6.5 → 6.0 mm
Compatibility & fit
Works with ER-8 collet chucks on BT/CAT/HSK/straight-shank holders. Ensure your nut matches ER-8 (M10×1.0 thread, UM/Hex/Mini styles). For sealed setups, use sealed collets (or sealing disks where applicable) and a compatible nut.
Care & best practices
- Keep collet, nut, and taper spotless; light oil film only—debris hurts TIR.
- Match tool shank tolerance (h6/H6) for grip and life.
- Replace collets that show wear, spring fatigue, or crash damage; accuracy degrades before it's visible.
Technical specifications
| Property | Value |
|---|---|
| Series | ER-8 |
| Nominal size options | 0.5–5 mm (incl. 0.5 steps) |
| Clamp range (Standard) | nominal → nominal − 1.0 mm |
| Clamp range (Sealed) | nominal → nominal − 0.5 mm |
| Accuracy tiers (collet-only) | ≤15 µm TIR · ≤8 µm TIR · ≤5 µm TIR (measured at bore, 20 °C) |
| Standard | ISO 15488 / DIN 6499-B |
| Material | Hardened alloy spring steel, precision ground (INOX stainless optional) |
| Finish | Ground; optional black oxide |
| Slots | Multi-slit elastic (ER) |
| Balance grade (typ.) | G2.5 (system balance depends on holder/nut) |
| Max RPM (typ.) | Holder-limited (see your ER-8 chuck/nut datasheet) |
| Type options | Standard (vented) · Sealed (coolant-through) |
| Nut thread | M10×1.0 (standard ER-8 nut) |
| Recommended torque | 10–20 Nm (varies by nut style) |
FAQ
Q: What size range does ER-8 really cover? A: Individual ER-8 collets clamp roughly 1 mm of collapse each. A full set in 1 mm steps spans the series' working range (0.5–5 mm for ER-8).
Q: How "precision" is a good ER-8 collet? A: Standard quality is ≤15 µm TIR, while high-precision grades achieve ≤8 µm and ultra-precision ≤5 µm (collet-only, measured at bore).
Q: Do I need sealed collets for through-coolant tools? A: Yes—sealed ER-8 collets block coolant bleed and deliver pressure to the tool tip; many are rated ~2000 psi (138 bar).
What's included
- 1× ER-8 collet (selected nominal) in a labeled protective tube
- Label shows size • accuracy tier • batch ID (QR → datasheet & torque chart)
Quality & Installation Standards
SKU Format: AS-ER8-[SIZE]-[ACCURACY] (e.g., AS-ER16-1200-HP for 12mm High Precision)
Quality Control:
- Batch QC with precision gage pins at 20°C reference
- Collet-only TIR measurement at bore
- Visual inspection for surface defects and slot integrity
- Traceable manufacturing batches with QR codes
Installation Best Practices:
- Always clean taper and collet before assembly
- Snap collet into nut before threading onto chuck
- Use calibrated torque wrench per manufacturer specifications
- Never tighten empty collet - always insert tool shank
- Check tool shank sits in upper half of clamp range for best TIR
- Replace collets showing nicks, discoloration, slot cracks, or out-of-spec TIR
Sealed vs Standard — when to choose
| Need | Pick |
|---|---|
| Through-coolant, keep chips/coolant out of slots | Sealed (0.5 mm collapse) |
| Maximum size coverage per collet | Standard (1.0 mm collapse) |
Accuracy & setup notes (for seasoned users)
- Published TIR is collet-only. System TIR (holder+collet+tool) depends on chuck grade, nut style, torque, cleanliness, and shank geometry.
- For finishing/micro tools: choose Ultra Precision, a balanced holder, and a bearing nut; keep shank engagement high.
Helpful reminders
- Don't clamp on flutes or Weldon flats.
- Replace collets showing nicks, discoloration, slot cracks, or out-of-spec TIR.
- Store dry; keep separate sets for roughing vs finishing to extend life.
ER-8 Spring Collet — ISO 15488 / DIN 6499 (8°)
Universal, high-grip tool holding for mills, lathes, routers & grinders. ER-8 collets follow the ISO 15488 / DIN 6499 standard (8°) and are compatible with any ER-8 chuck.
Choose your accuracy
- Standard (≤15 µm TIR) — dependable everyday accuracy.
- High-Precision (≤8 µm TIR) — tighter runout for better finish & tool life.
- Ultra-Precision (≤5 µm TIR) — finishing-grade concentricity; also available as sealed coolant collets in this grade.
Optional: With matched premium holders (e.g., balanced G2.5), system runout can reach ≤3 µm.
Pick your inner hole size (ID)
Metric IDs from 0.5 mm → 5 mm in 1 mm steps (and 0.5 mm half-steps). Each ER-8 collet normally collapses ~1 mm (e.g., 6.0 grips 6.0→5.0 mm). Very small IDs (≈≤3 mm) have a reduced collapse (~0.38 mm).
Quick size guide (examples)
- 0.5–3 mm: PCB tools / micro-drills (reduced collapse).
- 4–8 mm: General drilling, light milling.
- 5 mm: Larger drills/end mills within ER-8 envelope; verify tool shank tolerance (h6/H6) for best grip.
Choosing your size (step-by-step)
- Measure the shank (e.g., Ø 6.0 mm h6).
- Pick the collet nominal ≥ shank—never clamp above nominal.
- Prefer the closest nominal (e.g., 6.0 for a 6.0 mm shank; not 7.0).
- Decide type:
- Standard (vented) → 1.0 mm collapse (better range).
- Sealed (coolant-through) → 0.5 mm collapse (keeps chips/coolant out).
- Pick accuracy: ≤15 µm TIR, ≤8 µm TIR, ≤5 µm TIR (collet-only, at bore, 20 °C).
Why machinists choose ER-8
- Wide clamping range, fewer changeovers. Each ER collet provides ~1 mm collapse (commonly 1 mm steps across a set), so a 6 mm ER-8 collet securely clamps 6.0 → 5.0 mm. This minimizes inventory and speeds setups.
- Proven accuracy. Quality ER collets hold ≤15 µm TIR / ≤8 µm TIR / ≤5 µm TIR (collet-only TIR), boosting tool life and surface finish.
- Built for performance. Made from hardened spring steel and precision-ground for repeatable concentricity and grip.
- Coolant-through options. Sealed ER-8 collets support through-tool coolant—many rated to ~2000 psi (138 bar).
- Universal compatibility. Fits any ER-8 collet chuck (BT, CAT, HSK, straight-shank, etc.); use with UM/Hex/Mini nuts (standard M10×1.0 thread for ER-8).
Key specifications (ER-8)
- Standard: ISO 15488 / DIN 6499 (ER system, 8° taper)
- Clamping range: ~1 mm (per collet), sets typically in 1 mm steps
- Accuracy grades:
- Standard: ≤15 µm TIR (collet-only)
- High Precision: ≤8 µm TIR (collet-only)
- Ultra Precision: ≤5 µm TIR (collet-only)
- Shank tolerance: h6/H6 recommended for best performance
- Nut interface: UM/Hex/Mini; M10×1.0 (std. ER-8 nut thread)
- Coolant: Open (standard) or sealed (coolant-through) options available; sealed types often rated to ~2000 psi
Tip on torque: Typical recommended tightening torque for ER-8 nuts ranges 10–20 Nm, varying by nut style (castle/slotted/hex) and tool diameter—always follow your nut/chuck maker's table.
Coolant-through options
Select Sealed (coolant-through) ER-8 collets to deliver pressure to the tool tip; many are rated up to ~2000 psi. Use on-size sealed collets (no collapse) for proper sealing.
What it's great for
- High-mix machining where fast tool swaps and wide coverage matter
- End mills, drills, reamers, routers (round shanks) in the 0.5–5 mm range (typical ER-8 set coverage)
- Applications needing coolant-through clamping (sealed ER-8)
How to install (for best TIR)
- Snap the collet into the nut first (engage the extractor ring)
- thread onto the chuck
- insert clean on-size shank
- tighten with a torque wrench to your nut/chuck table. Never tighten an empty collet. (Follow your holder's torque chart.) (Standards & maker docs reference this method to preserve runout.)
Available nominal sizes (ER-8)
0.5 → 5 mm (whole & half-steps) 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5
Clamp bands (examples) • Standard 6.0 → clamps 6.0 → 5.0 mm • Standard 6.5 → 6.5 → 5.5 mm • Sealed 6.0 → 6.0 → 5.5 mm • Sealed 6.5 → 6.5 → 6.0 mm
Compatibility & fit
Works with ER-8 collet chucks on BT/CAT/HSK/straight-shank holders. Ensure your nut matches ER-8 (M10×1.0 thread, UM/Hex/Mini styles). For sealed setups, use sealed collets (or sealing disks where applicable) and a compatible nut.
Care & best practices
- Keep collet, nut, and taper spotless; light oil film only—debris hurts TIR.
- Match tool shank tolerance (h6/H6) for grip and life.
- Replace collets that show wear, spring fatigue, or crash damage; accuracy degrades before it's visible.
Technical specifications
| Property | Value |
|---|---|
| Series | ER-8 |
| Nominal size options | 0.5–5 mm (incl. 0.5 steps) |
| Clamp range (Standard) | nominal → nominal − 1.0 mm |
| Clamp range (Sealed) | nominal → nominal − 0.5 mm |
| Accuracy tiers (collet-only) | ≤15 µm TIR · ≤8 µm TIR · ≤5 µm TIR (measured at bore, 20 °C) |
| Standard | ISO 15488 / DIN 6499-B |
| Material | Hardened alloy spring steel, precision ground (INOX stainless optional) |
| Finish | Ground; optional black oxide |
| Slots | Multi-slit elastic (ER) |
| Balance grade (typ.) | G2.5 (system balance depends on holder/nut) |
| Max RPM (typ.) | Holder-limited (see your ER-8 chuck/nut datasheet) |
| Type options | Standard (vented) · Sealed (coolant-through) |
| Nut thread | M10×1.0 (standard ER-8 nut) |
| Recommended torque | 10–20 Nm (varies by nut style) |
FAQ
Q: What size range does ER-8 really cover? A: Individual ER-8 collets clamp roughly 1 mm of collapse each. A full set in 1 mm steps spans the series' working range (0.5–5 mm for ER-8).
Q: How "precision" is a good ER-8 collet? A: Standard quality is ≤15 µm TIR, while high-precision grades achieve ≤8 µm and ultra-precision ≤5 µm (collet-only, measured at bore).
Q: Do I need sealed collets for through-coolant tools? A: Yes—sealed ER-8 collets block coolant bleed and deliver pressure to the tool tip; many are rated ~2000 psi (138 bar).
What's included
- 1× ER-8 collet (selected nominal) in a labeled protective tube
- Label shows size • accuracy tier • batch ID (QR → datasheet & torque chart)
Quality & Installation Standards
SKU Format: AS-ER8-[SIZE]-[ACCURACY] (e.g., AS-ER16-1200-HP for 12mm High Precision)
Quality Control:
- Batch QC with precision gage pins at 20°C reference
- Collet-only TIR measurement at bore
- Visual inspection for surface defects and slot integrity
- Traceable manufacturing batches with QR codes
Installation Best Practices:
- Always clean taper and collet before assembly
- Snap collet into nut before threading onto chuck
- Use calibrated torque wrench per manufacturer specifications
- Never tighten empty collet - always insert tool shank
- Check tool shank sits in upper half of clamp range for best TIR
- Replace collets showing nicks, discoloration, slot cracks, or out-of-spec TIR
Sealed vs Standard — when to choose
| Need | Pick |
|---|---|
| Through-coolant, keep chips/coolant out of slots | Sealed (0.5 mm collapse) |
| Maximum size coverage per collet | Standard (1.0 mm collapse) |
Accuracy & setup notes (for seasoned users)
- Published TIR is collet-only. System TIR (holder+collet+tool) depends on chuck grade, nut style, torque, cleanliness, and shank geometry.
- For finishing/micro tools: choose Ultra Precision, a balanced holder, and a bearing nut; keep shank engagement high.
Helpful reminders
- Don't clamp on flutes or Weldon flats.
- Replace collets showing nicks, discoloration, slot cracks, or out-of-spec TIR.
- Store dry; keep separate sets for roughing vs finishing to extend life.
