BEYOND S20R-SDUCL11 Internal Boring Bar 20mm Shank CNC Lathe Turning Tool Holder Left Hand
BEYOND S16Q-SDUCR07 Internal Boring Bar 16mm Shank CNC Lathe Turning Tool Holder Right Hand
BEYOND S16Q-SDUCL11 Internal Boring Bar 16mm Shank CNC Lathe Turning Tool Holder Left Hand
BEYOND S16Q-SDUCL07 Internal Boring Bar 16mm Shank CNC Lathe Turning Tool Holder Left Hand
BEYOND S14N-SDUCR07 Internal Boring Bar 14mm Shank CNC Lathe Turning Tool Holder Right Hand
BEYOND S12M-SDUCR11 Internal Boring Bar 12mm Shank CNC Lathe Turning Tool Holder Right Hand
BEYOND S12M-SDUCR07 Internal Boring Bar 12mm Shank CNC Lathe Turning Tool Holder Right Hand
BEYOND S12M-SDUCL07 Internal Boring Bar 12mm Shank CNC Lathe Turning Tool Holder Left Hand
BEYOND S08K-SDUCR07 Internal Boring Bar 8mm Shank 125mm Length Screw Clamped Right Hand 93-Degree DCMT 0702 Lathe Turning Tool Holder
BEYOND S08K-SDUCL07 Internal Boring Bar 8mm Shank CNC Lathe Turning Tool Holder Left Hand
Browse 82 BEYOND DC INSERT round-shank boring bars for DCMT/DCGT 55° rhombic inserts (7° positive relief). All bars are manufactured from vacuum-quenched alloy steel (DIN 1.3343/AISI M2 equivalent), heat-treated to HRC 60-62, and precision-ground for ±0.01mm shank and pocket tolerances. Same-day shipping to 50+ countries via DHL/UPS/FedEx. ISO 9001 certified.
Internal Boring Bar vs External Turning Holder — Key Differences
Boring bars (internal turning tool holders) and external turning holders have different shank specifications but share the same ISO 1832 5-letter insert interface code. A boring bar cannot replace an external holder and vice versa.
| Spec | External Turning Holder | Internal Boring Bar (this catalog) |
|---|---|---|
| Shank shape | Square (mm × mm) | Round (single mm diameter) |
| Position 2-3 | Shank height × width (e.g. 2525 = 25×25 mm) | Shank diameter (e.g. 25 = 25 mm round) |
| Position 4 | Shank length code (H/K/M/P/Q) | Same length codes — typically shorter than external |
| Typical sizes | 16 / 20 / 25 / 32 mm square | 8 / 10 / 12 / 14 / 16 / 20 / 25 / 32 mm round (smaller for small holes) |
| Position 5 | Shank width (mm) | Separator "-" |
| Insert IC code | 12 / 16 / 19 / 22 / 25 mm (larger) | 07 / 11 (6.35/9.525 mm — smaller for tight bores) |
| Optional -A## suffix | None | Minimum bore diameter (e.g. -A12 = 12 mm min bore, anti-vibration bars) |
| Application | Turning the OUTER diameter of workpiece | Turning the INNER diameter (boring a hole from inside) |
| Coolant | Often without | Coolant-through is standard for chip evacuation |
Critical note: A boring bar and an external turning holder with the same 5-letter code (e.g. SDUCR) have different shank diameters and lengths. They are NOT interchangeable.
Compatible Inserts: DCMT/DCGT 11 Family
BEYOND DC INSERT boring bars accept the ISO 1832 D-shape insert family, primarily DCMT 11 (55° rhombic, 7° positive relief) for general-purpose internal turning, and DCMT 07 (smaller IC) for tight-bore applications.
| Insert Family | IC | Relief | Best For | Compatible BEYOND DC Bar |
|---|---|---|---|---|
| DCMT 11T3 | 9.525 mm | 7° positive | Steel & stainless internal turning (most common) | S##R/S##S/S##T-SD*CR/L11 series |
| DCMA 11T3 | 9.525 mm | 7° positive (no chip-breaker) | Heavy roughing internal profiling | S##R/S##S/S##T-SD*CR/L11 series |
| DCGT 11T3 | 9.525 mm | 7° positive | Aluminum + brass + plastics finishing | SD* compatible (positive geometry) |
| DCMT 0702 | 6.35 mm | 7° positive | Small-bore steel internal turning | S08K/S10K/S12M/S14P/S16Q-SD*CR07 series |
| DCGT 0702 | 6.35 mm | 7° positive | Small-bore aluminum finishing | SD* compatible (positive geometry) |
| DCMW 11T3 | 9.525 mm | 7° positive (wiper geometry) | Surface finish optimization on internal turning | SD* compatible (wiper insert) |
Browse our VB INSERT Internal Boring Bars for 35° rhombic insert alternatives, or use our Grade Cross-Reference Hub to find DCMT equivalents across 8 brands (Mitsubishi, Sandvik, Kyocera, Tungaloy, KORLOY, Sumitomo, ZCC.CT, Walter).
BEYOND DC INSERT 12-Position Boring Bar Code
The BEYOND DC INSERT boring bar code is a 12-position extended naming convention that adds shank specification before the 5-letter ISO 1832 insert interface code. Positions 1-5 define the boring bar shank, positions 6-10 are the standard 5-letter code, position 11 is insert IC, and optional position 12 specifies minimum bore diameter:
| Position | Symbol | Meaning |
|---|---|---|
| 1 | S | Boring bar round-shank indicator (vs. square-shank external holder). Internal coolant-through design is standard. |
| 2-3 | 08 / 10 / 12 / 14 / 16 / 20 / 25 / 32 | Shank diameter (mm) — single mm value (round shank). Smaller diameters (08/10/12/14) for tight bores; larger (20/25/32) for heavy roughing. |
| 4 | K / M / P / Q / R / S / T | Shank length code — K=125mm / M=150mm / P=170mm / Q=180mm / R=200mm / S=250mm / T=300mm. |
| 5 | - | Separator dash between shank spec and 5-letter code. |
| 6-10 | 5-letter code | Same 5-letter ISO 1832 code as external holders — Pos 6 = clamping mode (S=screw-clamp), Pos 7 = insert shape (D=55° rhombic), Pos 8 = approach angle (U=93° / W=60° / Q=45° / X=variable / Z=15°), Pos 9 = relief angle (C=7° positive), Pos 10 = hand (R=right / L=left). |
| 11 | 07 / 11 | Insert IC code — 07 = 6.35 mm (DCMT 0702); 11 = 9.525 mm (DCMT 11T3). |
| 12 (optional) | -A## | Minimum bore diameter code — only present on stepped/anti-vibration bars (e.g. -A25 = 25 mm minimum bore). |
Example: S20R-SDUCR11 = S (boring bar) + 20 (20 mm round shank) + R (200 mm length) + SDUCR (Screw-clamp + D 55° rhombic + U 93° approach + C 7° positive relief + R right-hand) + 11 (9.525 mm insert IC). S25S-SDXCL11 = S + 25 + S (250 mm) + SDXCL (left-hand) + 11.
Shank × 5-Letter Code Spec Matrix
The 82 BEYOND DC INSERT SKUs are organized by shank diameter and 5-letter insert interface code:
| 5-Letter Code | 8 mm | 10 mm | 12 mm | 14 mm | 16 mm | 20 mm | 25 mm | 32 mm | Insert IC |
|---|---|---|---|---|---|---|---|---|---|
| SDUCR (right) | — | — | — | — | 1 | 3 | 3 | 3 | 11 |
| SDUCL (left) | — | — | — | — | 1 | 2 | 2 | 2 | 11 |
| SDZCR (right) | — | — | — | — | 1 | 1 | 2 | 2 | 11 |
| SDZCL (left) | — | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 11 |
| SDWCR (right) | — | 1 | 1 | — | 1 | 1 | 1 | 1 | 11 |
| SDWCL (left) | — | — | 1 | — | 1 | 1 | — | 1 | 11 |
| SDQCR (right) | — | 1 | — | — | 1 | 1 | — | — | 11 |
| SDQCL (left) | — | — | — | — | 1 | 1 | — | — | 11 |
| SDXCR (right) | — | 1 | 1 | — | 1 | 1 | 1 | — | 11 |
| SDXCL (left) | 1 | 1 | 1 | 1 | 1 | 1 | 1 | — | 11 |
| DCMT 0702 (smaller IC) | 3 | 4 | 5 | 2 | 8 | 1 | — | — | 07 |
Speeds & Feeds for DC INSERT Boring Bars
Starting Vc values for DCMT 11 inserts in DC bars, by shank diameter and material. Boring Vc is typically 20-30% lower than external turning Vc due to chip evacuation constraints and tool overhang.
| Shank Diameter | Steel (P30) | Stainless (M20) | Cast Iron (K20) | Aluminum (N20) |
|---|---|---|---|---|
| 8 mm | Vc 140-200 m/min, f 0.08-0.15 mm/rev | Vc 90-140 m/min, f 0.06-0.12 | Vc 110-160 m/min, f 0.08-0.15 | Vc 200-400 m/min, f 0.06-0.15 |
| 12 mm | Vc 170-240 m/min, f 0.10-0.20 mm/rev | Vc 110-160 m/min, f 0.08-0.15 | Vc 140-200 m/min, f 0.10-0.18 | Vc 250-500 m/min, f 0.08-0.18 |
| 16 mm | Vc 200-280 m/min, f 0.12-0.25 mm/rev | Vc 140-200 m/min, f 0.10-0.18 | Vc 170-240 m/min, f 0.12-0.22 | Vc 300-600 m/min, f 0.10-0.22 |
| 20 mm | Vc 220-300 m/min, f 0.15-0.30 mm/rev | Vc 160-220 m/min, f 0.12-0.22 | Vc 190-260 m/min, f 0.15-0.28 | Vc 350-700 m/min, f 0.12-0.25 |
| 25 mm | Vc 240-320 m/min, f 0.18-0.32 mm/rev | Vc 180-240 m/min, f 0.15-0.25 | Vc 210-290 m/min, f 0.18-0.30 | Vc 400-800 m/min, f 0.15-0.28 |
| 32 mm | Vc 260-340 m/min, f 0.20-0.35 mm/rev | Vc 200-260 m/min, f 0.15-0.28 | Vc 230-310 m/min, f 0.20-0.32 | Vc 450-900 m/min, f 0.18-0.30 |
Speeds must be reduced 30-50% when using long overhang (overhang > 4× shank diameter) without anti-vibration bars. For anti-vibration bars with built-in tuned-mass dampers, speeds can be increased 10-20% at overhangs up to 6× shank diameter. For threading parameter guidance, see our Speeds & Feeds Hub.
DC INSERT vs VB INSERT — How to Choose
Both DC INSERT and VB INSERT are internal boring bar families, but they serve different niches:
| Spec | VB INSERT (35° Rhombic) | DC INSERT (55° Rhombic) |
|---|---|---|
| Insert shape | 35° rhombic (V-shape, narrower) | 55° rhombic (D-shape, wider) |
| Insert IC options | 11 (9.525 mm) and 16 (15.875 mm) | 07 (6.35 mm) and 11 (9.525 mm) |
| 5-letter code prefix | SV* (V-shape + screw-clamp) | SD* (D-shape + screw-clamp) |
| Best for | Heavy internal turning (steel/cast iron), larger bores | General internal turning (steel/stainless), wider geometry tolerance |
| Strengths | Stronger edge geometry for heavy roughing | Wider chipformer selection, more versatile |
| Boring bar count | 50 SKUs (6 shank diameters) | 82 SKUs (8 shank diameters — more size options) |
Quick rule: Choose DC INSERT for general-purpose internal turning (most common — 80% of boring applications). Choose VB INSERT for heavy-duty roughing on steel/cast iron where edge strength matters more than versatility.
Applications: When to Use DC INSERT Internal Boring Bars
BEYOND DC INSERT boring bars cover the four most common internal turning scenarios on CNC lathes:
- General internal turning — 16/25 mm shank with DCMT 11 PVD sharp edge (TiAlN) for finish boring to ±0.01 mm tolerance on stainless and alloy steel. The workhorse geometry for 80% of boring applications.
- Small-bore internal turning — 8/10/12 mm shank with DCMT 0702 (IC 6.35 mm) inserts for bores < 12 mm where DC11 cannot physically fit.
- Deep-hole boring — 32 mm shank with anti-vibration for bores > 6× shank diameter depth (e.g. hydraulic cylinder barrels, valve bodies).
- Aluminum finishing — DCGT 11 inserts (mirror-polished rake face, H01 un-coated) for aluminum, brass, and plastics at 800 m/min Vc with no built-up edge risk.
Material matrix: DC INSERT + DCMT 11 work on low-carbon steel, alloy steel, stainless steel (300/400 series), aluminum alloys, brass, and cast iron. For specific material-grade matching, see Carbide Inserts by Material.
Why Choose BEYOND DC INSERT Boring Bars
- Screw-Clamp Clamping (SD* Series) — All 82 BEYOND DC INSERT SKUs use screw-clamp (S-type) clamping — the dominant clamping system for boring bars with reliable chip flow and easy insert indexing.
- Anti-Vibration Ready — Bars with the -A## suffix (minimum bore diameter) are anti-vibration design with built-in tuned-mass dampers, allowing boring at overhangs up to 6× shank diameter with the same surface finish as 3× overhang standard bars.
- 30-50% Below OEM Price — BEYOND DC INSERT boring bars match the ISO 1832/ISO 5608 dimensional specs of Sandvik, Kyocera, and Mitsubishi equivalents at 30-50% lower landed price.
- Drop-In Compatible with Major Brands — BEYOND DC INSERT boring bars are dimensionally identical to leading carbide insert brands per ISO 1832 (insert shape) and ISO 5608 (insert pocket). Sandvik, Kyocera, Mitsubishi, Sumitomo, Korloy, ZCC.CT, Walter, and Iscar DCMT 11 inserts all fit with matching 5-letter codes.
Six Topic Cluster Pillars
Reading from the Field
Frequently Asked Questions
How do I distinguish a BEYOND DC INSERT boring bar from an external turning holder?
The boring bar code starts with "S" followed by the shank diameter (round), while external holders use the clamp mode letter followed by shank height and width (square). For example, S20R-SDUCR11 is a 20 mm round shank boring bar with screw-clamp clamping for DCMT 11 inserts. The equivalent external holder would be SDUCR2020K11 with 20×20 mm square shank. Same 5-letter insert interface, different shank geometry.
What is the minimum bore diameter a DC INSERT boring bar can machine?
The minimum bore diameter depends on the shank diameter — the shank must physically fit inside the bore. For a 8 mm shank boring bar, minimum bore is approximately 10-12 mm. For 10 mm shank: 12-14 mm. For 12 mm shank: 14-16 mm. For 32 mm shank: 36-40 mm. Some boring bars include an optional -A## suffix indicating their certified minimum bore (e.g. -A25 = 25 mm minimum bore for a 20 mm shank bar).
What is an anti-vibration boring bar?
Anti-vibration (or "damped") boring bars have an internal tuned mass damper that absorbs chatter during deep boring operations. They allow boring at overhangs up to 6× shank diameter (vs. 3-4× for standard boring bars) with the same surface finish. They're identified by the -A## suffix or by tags like "anti-vibration" or "vibration damping".
What inserts do DC INSERT boring bars accept?
BEYOND DC INSERT boring bars accept ISO 1832 standard D-shape inserts in IC 07 (6.35 mm — DCMT 0702) and IC 11 (9.525 mm — DCMT 11T3) for steel, stainless, aluminum, and cast iron. Same inserts work on external holders with the matching 5-letter code. DCGT (7° positive relief) is for aluminum/brass/plastics; DCMA is for heavy roughing.
How do I select the right shank diameter for my boring application?
Choose the LARGEST shank that fits inside the bore, then ensure overhang is ≤ 3-4× shank diameter (or ≤ 6× for anti-vibration bars). Smaller shanks allow access to tighter bores but are more flexible (prone to chatter). Larger shanks are more rigid but require larger bore openings. For bores 10-12 mm use 8 mm shank. For bores 12-14 mm use 10 mm. For bores 14-16 mm use 12 mm. For deeper boring at high L/D ratio, choose anti-vibration bar variant.
Are DC INSERT boring bars compatible with Sandvik, Kyocera, Mitsubishi inserts?
Yes. BEYOND DC INSERT boring bars conform to ISO 1832 (insert shape) and ISO 5608 (insert pocket) dimensional standards, making them fully interchangeable with inserts from Sandvik Coromant, Kyocera, Mitsubishi, Sumitomo, Korloy, Iscar, Tungaloy, Walter, ZCC.CT, and TaeguTec. The DCMT 11 insert pocket geometry is identical across brands; only the chip-breaker shape and carbide grade differ.
Should I choose DC INSERT or VB INSERT for my boring application?
Choose DC INSERT (55° rhombic) for general-purpose internal turning — it's the workhorse geometry for 80% of boring applications on steel and stainless. Choose VB INSERT (35° rhombic) for heavy-duty roughing on steel/cast iron where edge strength matters more than chipformer versatility. DC INSERT has 82 SKUs across 8 shank diameters (more size options); VB INSERT has 50 SKUs across 6 shank diameters. If you're unsure, DC INSERT is the safer default — it's more versatile and easier to find cross-compatible inserts from any major brand.
Do you offer same-day shipping for DC INSERT boring bars to international destinations?
Yes. All 82 BEYOND DC INSERT boring bars ship same-day from our Hong Kong warehouse with DHL Express to US/EU destinations in 3-7 business days. We serve 50+ countries with ISO 9001 certified supply chain. Volume discounts: 2-9 pcs 6% off, 10+ pcs 12% off. For anti-vibration bar pricing or custom shank lengths, please contact us directly with your BEYOND DC INSERT reference (e.g., S20R-SDUCR11).
Get BEYOND DC INSERT Boring Bars Quoted in 24 Hours
Send us your BEYOND DC INSERT reference (e.g. S20R-SDUCR11 for 20 mm round shank, 200 mm length, DCMT 11 insert) and we will return a landed-price quote including DHL/UPS/FedEx freight to your country. Volume discounts: 2-9 pcs 6% off, 10+ pcs 12% off. We accept PO from hydraulic, valve, fastener, and general machining manufacturers. For anti-vibration bar pricing, please specify -A## suffix at time of quote.
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