BEYOND S16Q-STWNR16 Internal Boring Bar 16mm Shank 180mm Length Screw Fastened Right Hand 60-Degree TNMG 1604 Lathe Turning Tool Holder
BEYOND STWNR Internal Boring Bar — 60° Approach, 0° Negative Relief for TN Triangle Inserts (TNMG 16)
BEYOND STWNR Internal Boring Bars — Screw-Clamp Round-Shank Holders with 60° Approach (T-Family W Code) + 0° Negative Relief for TN INSERT (Triangle 60° TNMG 16 Inserts) for Heavy Roughing Boring
Browse the BEYOND STWNR boring bar collection — Screw-clamp round-shank holders with 60° approach + 0° negative relief for TN INSERT (TNMG 16) for heavy roughing internal turning.
Browse the full BEYOND Screw-On System Boring Bar catalog, or jump to: About · Shank Spec Decode · 5-Letter Code Reference · All Products · FAQ.
🔍 Internal Boring Bar vs External Turning Holder — Critical 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.
| 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. 06 = 6 mm round) |
| Position 4 | Shank length code (H/K/M/P/Q) | Shank length code (H/J/K/M/Q) — typically shorter than external |
| Typical sizes | 16 / 20 / 25 / 32 mm square | 6 / 8 / 10 / 12 / 16 / 20 / 25 / 32 mm round (smaller for small holes) |
| Position 5 | Shank width (mm) | Separator "-" |
| Position 6-10 (5-letter code) | Clamp + Shape + Approach + Relief + Hand | Same 5-letter code (SCLCR / SDJCR / STUBR etc.) |
| Insert IC code | 12 / 16 / 19 / 22 / 25 mm (larger) | 06 / 07 / 08 / 09 / 11 / 12 mm (smaller for small holes) |
| Optional -A## suffix | None | Minimum bore diameter (e.g. A12 = 12 mm min bore, for stepped / anti-vibration bars) |
| Application | Turning the OUTER diameter of workpiece | Turning the INNER diameter (boring a hole from inside) |
| Insert side | Insert's top rake faces OUTWARD on the shank's top | Insert's top rake faces INWARD — chip flow goes UP/OUT through the bore |
| 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.
BEYOND-Original Boring Bars from Hangzhou, China
All 1 boring bars in this catalog are 100% genuine BEYOND — manufactured by BEYOND in Hangzhou, China. Each boring bar is CNC-machined from premium alloy steel (DIN 1.3343 / AISI M2 equivalent), heat-treated to HRC 60-62, and precision-ground for shank and pocket tolerances within ±0.01mm. Most boring bars include internal coolant channels (coolant-through design) for efficient chip evacuation during deep boring operations. Many models feature anti-vibration damping for chatter-free boring at overhangs up to 6× shank diameter.
About BEYOND Screw-On System Boring Bars
Boring bars (internal turning tool holders) are designed to reach inside a pre-existing hole and enlarge it or finish the inner surface to a precise diameter. They have round shanks (not square like external holders) so they can fit through the bore opening, and they typically feature internal coolant channels for chip evacuation through the bar itself.
This catalog contains 1 BEYOND boring bar SKUs across 1 unique 5-letter codes, 1 shank diameter options, and 1 length codes. All holders are screw-clamp (the dominant clamping system for boring bars) with standard ISO 1832 5-letter insert interface codes.
BEYOND 9-Position Boring Bar Code Structure (per official catalog):
| Position | Symbol | Meaning |
|---|---|---|
| 1 | S | Boring bar round-shank indicator — the "S" prefix designates a round-shank boring bar (vs. square-shank external holder). Internal coolant-through design is standard. |
| 2-3 | 06 · 08 · 10 · 12 · 16 · 20 · 25 · 32 | Shank diameter (mm) — single mm value (round shank, not height×width). Smaller diameters (06/08/10) are for tight bores; larger (25/32) for heavy roughing. |
| 4 | H · J · K · M · N · Q · R · S | Shank length code — 24 letters A-Y encoding 32-500mm. Common boring bar lengths: H=100mm / J=110mm / K=125mm / M=150mm / Q=180mm / R=200mm. |
| 5 | - | Separator dash between shank spec and 5-letter code. |
| 6-10 | S · M · C · D · P · A · W | 5-letter ISO 1832 code (same as external holders) — Pos 6 = clamping mode, Pos 7 = insert shape, Pos 8 = approach angle, Pos 9 = relief angle, Pos 10 = hand direction. |
| 11 | 06 · 07 · 08 · 09 · 11 · 12 | Insert IC code — 06 = 6.35mm / 07 = 7.94mm / 08 = 7.94mm / 09 = 9.525mm / 11 = 11.0mm / 12 = 12.7mm. Boring bars typically use SMALLER inserts than external holders (06/08/11 are common for boring). |
| 12+ | -A## (optional) | Minimum bore diameter code — only present on stepped/anti-vibration bars. e.g. -A12 = 12mm minimum bore diameter. |
Boring Bar Shank Specification Distribution
BEYOND boring bars are available in 1 shank diameters — from 6mm (for tight bores) to 32mm (for heavy roughing). The shank must be smaller than the bore being machined, leaving clearance for chip evacuation on the shank's underside.
| Shank Diameter | SKU Count | Typical Use Case |
|---|---|---|
| 16 mm round shank | 1 | For boring holes as small as ~18-24 mm diameter |
5-Letter Insert Interface Codes
Despite being boring bars (internal), the 5-letter ISO 1832 code follows the same convention as external turning holders. Each card below shows one 5-letter code with its decoding and SKU count.
STWNR — Triangle 60°-shape
Screw-Clamp + 60° approach + 0° negative relief + Right-hand
Featured BEYOND Screw-On System Boring Bars
Top featured boring bars from this collection — click any to view product details, insert specifications, and add to cart.
BEYOND S16Q-STWNR16 Internal Boring Bar 16mm Shank 180mm Length Screw Fastened R…
BEYOND · 16mm Shank · Alloy Steel · BEYOND
Browse BEYOND Boring Bar SKUs (Sample of 1+ in this Collection)
Showing top 30 boring bars (sample of all 1 SKUs in this collection) — view the complete catalog at /collections/stwnr-l-internal or use the search function for specific codes.
| Product Handle | Title (preview) | SKU Code |
|---|---|---|
| s16q-stwnr16-boring-bar-internal-turning-tool-holder | BEYOND S16Q-STWNR16 Internal Boring Bar 16mm Shank 180mm Length Screw … | S16Q-STWNR16 |
+ additional SKUs not shown in this table — visit the full collection page to browse all products.
Need Help Selecting the Right Boring Bar?
Choosing a boring bar requires knowing: (1) bore diameter to be machined, (2) depth of cut / overhang length, (3) workpiece material, (4) shank rigidity needs. Our CNC specialists help match the right S##L shank diameter, length code, and 5-letter insert code to your application. Contact us for a same-day quote.
Request Quote · Request Sample Catalogs · Browse All BEYOND Tool Holders
Frequently Asked Questions
How do I distinguish a BEYOND boring bar from an external turning holder?
The first letter is always "S" in boring bars (round-shank indicator). External turning holders start with their clamp mode letter (S=screw, M=multi-lock, D=dual). So: - S06K-SCLCR06 = boring bar, 6mm round shank, 125mm length, SCLCR insert interface - S2525K-SCLCR12 = external turning holder, 25×25mm square shank, 125mm length, same SCLCR insert interface The 5-letter code (SCLCR) is the same; only the shank specification differs.
What's the minimum bore diameter a boring bar can machine?
The minimum bore diameter depends on the shank diameter — the shank must physically fit inside the bore. For a 6mm shank boring bar, minimum bore is approximately 8-10mm. For 8mm shank: ~10-12mm. For 12mm shank: ~14-16mm. For 32mm shank: ~36-40mm. Some boring bars include an optional "-A##" suffix indicating their certified minimum bore (e.g. -A12 = 12mm minimum bore for an 8mm shank bar).
What's 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 BEYOND boring bars accept?
BEYOND boring bars accept ISO 1832 standard CCMT / DCGT / TCMT / SCMT / VCMT inserts (positive 7° relief) and CNMG / DNMG / SNMG / TNMG / VNMG inserts (negative 0° relief) — same as external holders. The insert IC code is in Position 11 of the boring bar code. Most boring bars use small inserts (IC 06/07/08/09/11/12 = 6.35-12.7mm) to keep the bar's cutting edge compact enough to fit inside tight bores.
What's the difference between boring bar shank diameters?
Boring bar shank diameters range from 5mm (smallest, for tiny bores) to 50mm (largest, for heavy roughing of big holes). Smaller shanks allow access to tighter bores but are more flexible (prone to chatter). Larger shanks are more rigid but require larger bore openings. The general rule: choose the LARGEST shank that fits inside the bore, then ensure overhang is ≤ 3-4× shank diameter (or ≤ 6× for anti-vibration bars).
How do I decode the 5-letter ISO code on a BEYOND boring bar?
5-letter codes on boring bars are identical to those on external holders: - Letter 1 = clamping mode (S = screw-clamp, M = multi-lock, D = dual) - Letter 2 = insert shape (C=80° rhombic, D=55° rhombic, S=square, T=triangle, V=35° rhombic, R=round) - Letter 3 = approach angle (A=90°, B=75°, C=90°/45° sec, J=93°, L=95°, Q=107.5°, etc.) - Letter 4 = relief angle (B=5° positive, C=7° positive, D=15° positive, N=0° negative, P=11° positive) - Letter 5 = hand (L=left, N=universal, R=right) Example: SCLCR = Screw-clamp + 80° rhombic + 95° approach + 7° positive relief + Right-hand
Are BEYOND boring bars compatible with Sandvik, Kyocera, Mitsubishi inserts?
Yes. BEYOND boring bars accept ISO 1832 standard inserts from all major brands — Sandvik Coromant, Kyocera, Mitsubishi, Sumitomo, Korloy, Iscar, Tungaloy, Walter, ZCC.CT, Taegutec. The insert pocket geometry is identical across brands; only the chip-breaker shape and carbide grade differ.
Explore BEYOND Tool Holder Catalogs
Browse BEYOND's full tool holder family — internal boring, external turning, threading, grooving, parting:
All BEYOND Screw-Clamp External Holders
Top-level root for screw-clamp (Position 1 = S) external turning holders — square shank (16/20/25/32 mm). Same 5-letter insert code as boring bars but for outside diameters.
All BEYOND Multi-Lock External Holders
Top-level root for multi-lock external holders (Position 1 = M) — heavy-duty interrupted cuts and forged-skin removal.
BEYOND Master Catalog
Complete BEYOND tool holder lineup across external, boring, threading, and grooving applications — plus BEYOND carbide inserts.
All BEYOND + OYYU Products
Full combined catalog: BEYOND house brand + OYYU brand + Mitsubishi / Kyocera / Sandvik / Sumitomo / Korloy / Taegutec / Walter / Iscar / Tungaloy / ZCC.CT inserts.