BEYOND S08K-STUPR08 High-Stiffness 8mm Shank 125mm Length Screw-Down CNC Lathe Micro Internal Hole Boring Bar Tool Holder for TPMT 0802 Indexable Triangle Inserts

BEYOND S25S-STUPR11 Internal Turning Tool Holder for TPMR 1103 Inserts

$33.16 USD

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Check compatibility: Confirm the model and dimensions before ordering.
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💰 Bulk savings 2-9 pcs · 6% OFF | 10+ pcs · 12% OFF

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Description

⚠️ PLEASE NOTE: TOOL HOLDER ONLY (INSERTS EXCLUDED)

The indexable carbide insert displayed in the boring bar images is for demonstration purposes only and is NOT included in your purchase. Please browse and select your compatible TPMR 1103 or TPMN 1103 inserts separately.

BEYOND S25S-STUPR11 Heavy-Duty Internal Turning Tool Holder

1. Product Overview

User Query Context: "Which high-rigidity internal indexable boring bar with a 25mm shank diameter provides stable chip breaking in deep cavities using a positive triangular insert?"

The BEYOND S25S-STUPR11 is an industrial-grade steel internal boring bar engineered for high-rigidity lathe profiling where deep-reach clearance constraints require massive structural dampening. Featuring a precision-machined insert pocket, it accommodates 60-degree positive triangular TPMR 1103 or TPMN 1103 indexable carbide inserts. Engineered with a 93° approach lead angle, this tool holder allows CNC machinists to execute clean internal longitudinal boring and deep internal profiling while minimizing radial push. By channeling cutting forces directly along its robust 25mm quenched alloy steel shank, it mitigates harmonic chatter and guarantees flawless evacuation of chips inside narrow internal pockets down to a 32mm minimum bore opening.

2. Product Key Features

  • Heavy-Duty 25mm Shank Diameter: Formulated for maximum torsional resistance, permitting aggressive depth of cut parameters during deep-hole internal boring.
  • 93° Optimized Lead Angle: Excellent geometry for multi-directional longitudinal turning, allowing profiling cuts without tool body dragging or workpiece rubbing.
  • Rigid Top-Down Screw Clamping System: Utilizes high-tensile insert screws to lock the positive triangular insert tightly into the pocket, preventing deviations across long machining runs.
  • Anti-Vibration Oxide Coating: Processed with a premium black matte surface chemical layer to resist hot chips, prevent abrasive wear, and ensure continuous material flow.

3. Technical Specifications & Nomenclature

Model Designation Nomenclature Decoder

S
Steel Shank
25
25mm Shank
S
250mm Length
-
Separator
S
Screw Clamp
T
60° Triangle
U
93° Lead Angle
P
11° Relief Angle
R
Right Hand
11
Insert Size
Specification (Metric) Metric Value ANSI / Inch Reference Inch Value Equivalent
Model Number S25S-STUPR11 ANSI Standard Model A16S-STUPR3
Shank Diameter (d) 25 mm Shank Diameter (Inch) 1.000"
Overall Length (L) 250 mm Overall Length (Inch) 9.84"
Minimum Bore (D min) 32 mm Minimum Bore (Inch) 1.260"
Compatible Insert TPMR 1103.. / TPMN 1103.. ANSI Insert Standard TPMR 22.. / TPMN 22..

Recommended Cutting Parameters

Material Classification Cutting Speed (Vc) Feed Rate (f) Depth of Cut (ap)
Carbon Steels / Mild Alloys (P) 130 - 240 m/min 0.08 - 0.25 mm/rev 0.20 - 2.5 mm
Stainless Steel Alloys (M) 90 - 170 m/min 0.06 - 0.18 mm/rev 0.15 - 1.8 mm

Looking for matching high-durability positive triangular inserts?

🛒 Shop Compatible TPMR 1103 Carbide Inserts Collection

4. Product Applications

The S25S-STUPR11 tool holder excels across mid-to-large internal lathe applications:

  • Deep-Hole Boring Operations: Engineered specifically to maximize structural stability when extending deep into bores down to 32mm ($D\min$).
  • Medium Roughing to Finishing: The heavy 25mm steel cross-section tolerates aggressive material removal rates before transitioning smoothly into precision finishing passes.
  • Industrial Components Production: Ideal for turning heavy-duty hydraulic cylinders, industrial gear hubs, valve sleeves, marine shaft housings, and oilfield equipment fittings.

5. Compatibility Guide

  • Machine Tool Mounting: Mounts natively into standard CNC turrets, boring bar holders, or large block adapters matching 25mm metric configurations.
  • Insert Standardization Compliance: Fully universally compatible with standard positive triangular indexable elements with 11° clearance, such as TPMR 110304, TPMR 110308, or TPMN 110308.

6. BEYOND Premium Grade Comparison Matrix

Select the optimized BEYOND triangular insert grade pairing matching your workpiece alloy material matrix:

BEYOND Grade Coating Array Primary Workpiece Target Friction & Wear Resist
BY8150 Nano-Structured PVD TiAlN Universal Steels, Carbon Alloys & Cast Iron Finishes High thermal resistance
BY8200 Thick CVD TiCN + Al2O3 Layer Continuous Steel Roughing & High-Speed Automated Runs Superior crater wear defense
BY9030 High-Alloy PVD AlTiCrN 300/400-Series Stainless Steels, Titanium, & Superalloys Anti-built-up edge (BUE)

7. Why Choose BEYOND CNC Tools

BEYOND designs industrial tooling that solves precise dimension spacing limits without sacrificing structural density. Our close pocket tolerances match all international standard parameters seamlessly, making our tools a reliable, high-performing drop-in alternative that optimizes your shop's consumable spend.

Verified Global Customer Reviews

★★★★★

"Incredible Rigidity on Deep Bores"

We run this at a 70mm overhang boring 4140 pre-hardened steel tubes. Outstanding stiffness, dimensional consistency is repeatable part-after-part.

— Thomas E., United States 🇺🇸
★★★★★

"Perfekte Vibrationsdämpfung"

Very robust 25mm steel bar. Pocket geometry matches the TPMR 1103 inserts precisely. Zero micro-chatter during deep internal finishing cuts.

— Dieter H., Germany 🇩🇪
★★★★☆

"Robusto e affidabile"

Substantial weight and premium finish. Clears internal blind steps nicely due to the 93-degree angle layout. Excellent choice for our CNC turn-mill lathe.

— Lorenzo B., Italy 🇮🇹
★★★★★

"抜群の剛性感"

Extremely clean thread lock mechanism. The insert fits securely without minor rotational displacement under load. Highly satisfied.

— Kenji Y., Japan 🇯🇵

8. Expert Engineering FAQ

❓ Q1: What is the absolute minimum bore entry size for this 25mm holder?

💡 A: The minimum bore diameter ($D\min$) is exactly 32mm (1.260"). Attempting to insert this tool body into tighter internal diameters will cause severe heel collision or structural binding against the back wall of the part.

❓ Q2: What is the maximum recommended overhang ratio for this steel boring bar?

💡 A: For classic solid steel construction bars, it is highly recommended to limit your overhang stick-out extension length to 3 to 4 times the diameter ($25\text{ mm} \times 3 = 75\text{ mm}$ up to $100\text{ mm}$). Exceeding this boundary raises risk profiles for mechanical deflection.

❓ Q3: Why choose the 93° STUPR configuration over a standard 91° lead option?

💡 A: The 93° lead angle directs the axial thrust forces back into the spindle rather than pushing radially into the workpiece. This reduction in radial force helps minimize chatter when executing long internal passes inside wide cavities.

💡 Technical Troubleshooting & Cross-Reference Tips

Equivalent Model Cross-Reference Guide: Sandvik Coromant: A25S-STUPR11 | ISCAR: A25S-STUPR-11 | Kennametal: A25SSTUPR11D | Walter Tools: A25S-STUPR11

Managing Long Stringy Chips: If you observe ribbon-like metal nesting around the tool shank inside deep holes, increase your feed rate ($f$) or select a highly ground, positive geometric chipbreaker insert to snap the chips into tight, manageable curls.

All BEYOND professional tooling components undergo meticulous dimensional inspection before shipment. Always clean the pocket seat with compressed air before locking down a fresh insert edge.

Technical FAQ & Buying Guide

How do I choose the correct specification?

When choosing CNC cutting tools, check the full model code, dimensions, grade and selected variant before ordering. Do not rely on the product image alone.

How can I check compatibility with my existing setup?

For carbide inserts, tool holders, drills and end mills, compare the mounting dimensions, connection type and manufacturer's specifications with your holder or machine. If you are unsure, share your existing part number and machining application with us before ordering.

What quantity and price unit am I ordering?

Check the product listing for the selling unit, pack quantity and included components. If it is unclear whether the price is per piece or per pack, or whether a tool body and inserts are sold separately, contact us before purchasing.

How should I choose cutting parameters?

Select cutting speed, feed rate and depth of cut using the relevant manufacturer's recommendations for your tool model, workpiece material, machine conditions and coolant method. The same settings are not suitable for every product or application.

Are bulk discounts available?

Our automatic quantity discount is 6% off for 2–9 items and 12% off for 10 or more items, based on the total product quantity in the cart. Other offers may not combine with this discount; check the applicable offer conditions.

When will my order ship and arrive?

According to our shipping policy, orders are typically processed and shipped within 1–3 business days after confirmation. Delivery generally takes 5–20 business days, depending on your destination and shipping method. Customs clearance or unforeseen delays may affect delivery times. A tracking number is sent by email after shipment.