BEYOND S25S/S32T-MVZNR/L16 Indexable Internal Boring Bar Series (1.000" & 1.250" Shank) | Left & Right-Hand CNC Lathe Turning Tool Holder for VNMG1604 Inserts
BEYOND S32T-MVWNR16 (1-1/4" Shank) Indexable Internal Boring Bar | 32mm CNC Lathe Turning Tool Holder
BEYOND S32T-MVWNL16 (1-1/4" Shank) Indexable Internal Boring Bar | 32mm CNC Lathe Turning Tool Holder
BEYOND S25S-MVWNR16 (25mm / 0.984" Shank) Indexable Internal Boring Bar | Right-Hand 60° SCEA CNC Lathe Precision VNMG1604 Double-Direction Profiling Tool Holder
BEYOND S25S-MVWNL16 (1" Shank) Indexable Internal Boring Bar | 25mm CNC Lathe Turning Tool Holder
BEYOND S32T-MVUNR16 (1-1/4" Shank) Indexable Internal Boring Bar | 32mm CNC Lathe Turning Tool Holder
BEYOND S32T-MVUNL16 (1-1/4" Shank) Indexable Internal Boring Bar | 32mm CNC Lathe Turning Tool Holder
BEYOND S25S-MVUNR16 (1" Shank) Indexable Internal Boring Bar | 25mm CNC Lathe Turning Tool Holder
BEYOND S32T-MVXNR16 (1-1/4" Shank) Indexable Internal Boring Bar | 32mm CNC Lathe Turning Tool Holder
BEYOND S32T-MVXNL16 (1-1/4" Shank) Indexable Internal Boring Bar | 32mm CNC Lathe Turning Tool Holder
BEYOND S25S-MVXNR16 (1" Shank) Indexable Internal Boring Bar | 25mm CNC Lathe Turning Tool Holder
BEYOND S25S-MVXNL16 (1" Shank) Indexable Internal Boring Bar | 25mm CNC Lathe Turning Tool Holder
BEYOND S20R-MVWNR16 (3/4" Shank) Indexable Internal Boring Bar | 20mm CNC Lathe Turning Tool Holder
BEYOND S20R-MVXNL16 (20mm / 0.787" Shank) Indexable Internal Boring Bar | Left-Hand 117.5° CNC Lathe Profiling Tool Holder
BEYOND S32T-MVQNR16 (1-1/4" Shank) Indexable Internal Boring Bar | 32mm CNC Lathe Turning Tool Holder
BEYOND S32T-MVQNL16 (1-1/4" Shank) Indexable Internal Boring Bar | 32mm CNC Lathe Turning Tool Holder
BEYOND S25S-MVQNR16 (1" Shank) Indexable Internal Boring Bar | 25mm CNC Lathe Turning Tool Holder
BEYOND S25S-MVQNL16 (1" Shank) Indexable Internal Boring Bar | 25mm CNC Lathe Turning Tool Holder
BEYOND S20R-MVQNR16 (20mm / 0.787" Shank) Indexable Internal Boring Bar | Right-Hand 107.5° CNC Lathe Profiling Tool Holder
BEYOND S20R-MVQNL16 (3/4" Shank) Indexable Internal Boring Bar | 20mm CNC Lathe Turning Tool Holder
BEYOND VN INSERT Internal Boring Bars: 20 SKUs for VNMG 16 Inserts
BEYOND VN INSERT boring bars are multi-lock round-shank holders for internal turning on CNC lathes. Compatible with VNMG 16 negative-rhombic (35°) inserts, our 20-SKU VN catalog covers 8 distinct 5-letter codes (MVWNR / MVWNL / MVQNR / MVQNL / MVUNR / MVUNL / MVXNR / MVXNL) across three round shank diameters — 20 mm, 25 mm, 32 mm. Each boring bar is CNC-machined from vacuum-quenched alloy steel (DIN 1.3343 / AISI M2 equivalent), heat-treated to HRC 60-62, and precision-ground for shank and pocket tolerances within ±0.01 mm. Internal coolant channels standard for efficient chip evacuation during deep boring. Same-day shipping to 50+ countries via DHL / UPS / FedEx.
Internal Boring Bar vs. External Turning Holder — Key Differences
BEYOND VN INSERT 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 | 20 / 25 / 32 mm round (smaller for tight bores) |
| Position 5 | Shank width (mm) | Separator "-" |
| Position 6-10 (5-letter code) | Clamp + Shape + Approach + Relief + Hand | Same 5-letter code (MV* / MVWNR etc.) |
| Insert IC code | 12 / 16 / 19 / 22 / 25 mm (larger) | 16 (9.525-15.875 mm typical for boring) |
Optional -A## suffix |
None | Minimum bore diameter (e.g. -A12 = 12 mm min bore, for 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. SCLCR) have different shank diameters and lengths. They are NOT interchangeable — you cannot use a boring bar on an external turning job, nor an external holder inside a bore.
Compatible Inserts: VNMG 16 Family
BEYOND VN INSERT boring bars accept the ISO 1832 V-shape insert family, primarily VNMG 16 (35° negative rhombic, 0° relief) for heavy-duty internal turning:
| Insert Family | IC | Relief | Best For | Compatible BEYOND VN Bar |
|---|---|---|---|---|
| VNMG 1604 | 15.875 mm | 0° negative | Steel & cast iron heavy internal turning | All 20 SKUs (MVWNR / MVWNL / MVQNR / MVQNL / MVUNR / MVUNL / MVXNR / MVXNL) |
| VNMA 1604 | 15.875 mm | 0° negative (no chip-breaker) | Heavy roughing internal profiling | All 20 SKUs |
| VCGT 1604 | 15.875 mm | 7° positive | Stainless steel finishing internal | MV* compatible (positive geometry) |
| VCMT 1604 | 15.875 mm | 7° positive | Steel / stainless medium internal turning | MV* compatible |
Browse our threading insert collection for comparison, or use our Grade Cross-Reference Hub to find VNMG equivalents across 8 brands (Mitsubishi, Sandvik, Kyocera, Tungaloy, KORLOY, Sumitomo, ZCC.CT, Walter).
BEYOND VN INSERT 12-Position Boring Bar Code
The BEYOND VN 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 | 20 / 25 / 32 | Shank diameter (mm) — single mm value (round shank). Smaller diameters (20mm) are for tight bores; larger (32mm) for heavy roughing. |
| 4 | R / S / T | Shank length code — common boring bar lengths: 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 (M=multi-lock), Pos 7 = insert shape (V=35° rhombic), Pos 8 = approach angle, Pos 9 = relief angle (N=0°), Pos 10 = hand. |
| 11 | 16 | Insert IC code — 16 = 15.875 mm. |
| 12 (optional) | -A## | Minimum bore diameter code — only present on stepped / anti-vibration bars (e.g. -A25 = 25 mm minimum bore). |
Example: S25S-MVWNR16 = S (boring bar) + 25 (25 mm round shank) + S (250 mm length) + MVWNR (Multi-Lock + V-shape + W 60° approach + N 0° relief + R right-hand) + 16 (15.875 mm insert IC). S32T-MVZNR16 = S + 32 (32 mm shank) + T (300 mm length) + MVZNR + 16.
Shank × 5-Letter Code Spec Matrix
The 20 BEYOND VN INSERT SKUs are organized by shank diameter and 5-letter insert interface code. The table below maps all 20 SKUs by combination:
| 5-Letter Code | 20 mm Shank | 25 mm Shank | 32 mm Shank | Insert IC |
|---|---|---|---|---|
| MVWNR | S20R-MVWNR16 | S25S-MVWNR16 | S32T-MVWNR16 | 16 (15.875 mm) |
| MVWNL | — | S25S-MVWNL16 | S32T-MVWNL16 | 16 |
| MVQNR | S20R-MVQNR16 | S25S-MVQNR16 | S32T-MVQNR16 | 16 |
| MVQNL | S20R-MVQNL16 | S25S-MVQNL16 | S32T-MVQNL16 | 16 |
| MVUNR | — | S25S-MVUNR16 | S32T-MVUNR16 | 16 |
| MVUNL | — | — | S32T-MVUNL16 | 16 |
| MVXNR | S25S-MVXNR16 | S25S-MVXNR16 | S32T-MVXNR16 | 16 |
| MVXNL | S20R-MVXNL16 | S25S-MVXNL16 | S32T-MVXNL16 | 16 |
Speeds & Feeds for VN INSERT Boring Bars
Starting Vc values for VNMG 16 inserts in VN 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) |
|---|---|---|---|---|
| 20 mm | Vc 150-220 m/min, f 0.10-0.20 mm/rev | Vc 100-160 m/min, f 0.08-0.15 | Vc 120-180 m/min, f 0.10-0.18 | Vc 250-500 m/min, f 0.08-0.18 |
| 25 mm | Vc 180-260 m/min, f 0.12-0.25 mm/rev | Vc 120-180 m/min, f 0.10-0.18 | Vc 150-220 m/min, f 0.12-0.22 | Vc 300-600 m/min, f 0.10-0.22 |
| 32 mm | Vc 200-280 m/min, f 0.15-0.30 mm/rev | Vc 140-200 m/min, f 0.12-0.22 | Vc 180-260 m/min, f 0.15-0.28 | Vc 350-700 m/min, f 0.12-0.25 |
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.
Applications: When to Use VN INSERT Internal Boring Bars
BEYOND VN INSERT boring bars cover the four most common internal turning scenarios on CNC lathes:
- Deep-hole boring — 32 mm shank with anti-vibration for bores > 6× shank diameter depth (e.g. hydraulic cylinder barrels, valve bodies).
- Precision ID finishing — 20 mm shank with VNMG 16 PVD sharp edge (TiAlN) for finish boring to ±0.01 mm tolerance on stainless and alloy steel.
-
Vibration-sensitive boring — Anti-vibration bars (with
-A##suffix) for slender shafts and high L/D ratio bores where chatter would otherwise limit productivity. - Heavy-duty rough boring — 32 mm shank with VNMA 16 (no chip-breaker) for roughing cast iron and low-carbon steel at material removal rates up to 12 mm³/rev.
Material matrix: VN INSERT + VNMG 16 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 VN INSERT Boring Bars
BEYOND VN INSERT boring bars deliver four differentiators that matter most to production internal turning environments:
Multi-Lock Clamping (MV* Series)
All 20 BEYOND VN INSERT SKUs use multi-lock (M-type) clamping — multiple clamping points for the highest clamping force, ideal for heavy internal roughing and interrupted cuts. M-type clamping withstands 30-50% higher cutting forces vs. single-screw clamping (S-type).
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. Ideal for hydraulic cylinder boring and deep valve body work.
30-50% Below OEM Price
BEYOND VN INSERT boring bars match the ISO 1832 / ISO 5608 dimensional specs of Sandvik, Kyocera, and Mitsubishi equivalents at 30-50% lower landed price — same clamping force, same rigidity, same heat treatment (HRC 60-62).
Drop-In Compatible with Major Brands
BEYOND VN 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 VNMG 16 inserts all fit with matching 5-letter codes.
Explore Related Tooling & Resources
Six Topic Cluster Pillars
Pillar 1 — grade selection by workpiece material (P / M / K / N / S / H).
Pillar 2 — turning, milling, drilling, threading insert geometry.
Pillar 3 — decode ISO 1832 insert nomenclature (CNMG, WNMG, ADMT, VNMG).
Pillar 4 — equivalent grades across 8 brands (Mitsubishi / Sandvik / Kyocera / Tungaloy / KORLOY / TaeguTec / Sumitomo / ZCC.CT).
Pillar 5 — Vc / fz / ap starting parameters by material and operation.
Pillar 6 — boring bar / end mill holder / collet selection.
Other Brand Collections We Distribute
Japanese-origin carbide tooling with US7020 / UE6035 PVD grades.
PR series coated carbide turning inserts, CA6515 / PR1125 grades.
GC series turning + CoroDrill indexable drilling.
AC8025P / AC8035P CVD turning grades.
Japanese tooling with T9000 series turning inserts.
Korean carbide tooling with NC series turning + milling grades.
Korean tooling with TT8000 series turning grades.
Chinese carbide with YBC series turning + DNMG / CNMG families.
Israeli tooling with IC907 / IC908 chipformers.
German-engineered inserts under Tiger·tec® Silver (CVD) and Gold (PVD) coating platforms.
American KC™ grade system: KC5010 (live), KC7315, KC7325, KCK20, KCS10, KCP25 on-demand.
SNR / SNL boring bars for 08IR–27IR internal threading inserts.
BEYOND SER 53 SKUs for 11ER / 16ER / 22ER / 27ER external threading.
Reading from the Field
Identify genuine carbide vs HSS / coated HSS by spark test, weight, and edge geometry.
BT40 vs CAT40 vs HSK63A: taper standards, applications, and pull-stud compatibility.
Internal boring tool types for finishing, roughing, and contour work on CNC lathes.
Frequently Asked Questions
How do I distinguish a BEYOND VN 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, S25S-MVWNR16 is a 25 mm round shank boring bar with multi-lock clamping for VNMG 16 inserts. The equivalent external holder would be MVWNR2525M16 with 25×25 mm square shank. Same 5-letter insert interface, different shank geometry.
What is the minimum bore diameter a VN INSERT boring bar can machine?
The minimum bore diameter depends on the shank diameter — the shank must physically fit inside the bore. For a 20 mm shank boring bar, minimum bore is approximately 22-28 mm. For 25 mm shank: 27-33 mm. For 32 mm shank: 34-40 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 VN INSERT boring bars accept?
BEYOND VN INSERT boring bars accept ISO 1832 standard V-shape inserts in IC 16 (15.875 mm) — primarily VNMG 1604 (0° negative relief) for heavy-duty boring, plus VNMA 1604 (no chip-breaker for roughing) and VCGT / VCMT 1604 (7° positive relief for finishing stainless and aluminum). Same inserts work on external holders with the matching 5-letter code.
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 22-28 mm use 20 mm shank. For bores 27-33 mm use 25 mm shank. For bores 34-40 mm use 32 mm shank. For deeper boring at high L/D ratio, choose anti-vibration bar variant.
Are VN INSERT boring bars compatible with Sandvik, Kyocera, Mitsubishi inserts?
Yes. BEYOND VN 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 VNMG 16 insert pocket geometry is identical across brands; only the chip-breaker shape and carbide grade differ.
Request a Quote or VN INSERT Catalog
Get BEYOND VN INSERT Boring Bars Quoted in 24 Hours
Send us your BEYOND VN INSERT reference (e.g. S25S-MVWNR16 for 25 mm round shank, 250 mm length, VNMG 16 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.