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The Stainless Bros 1D / 1.75in CLR 90 Degree Bend 2in Leg Mandrel Bend (part number 601-04556-4100) is a compact tight-radius 90-degree tube section for 1.75-inch custom exhaust, turbo, and intercooler piping builds where space is at a premium. Precision-bent from 16-gauge 304 stainless steel, this component keeps the bore fully round through the 90-degree sweep to maintain flow in tight-clearance installations. The 1D radius at 1.75in CLR and the short 2-inch leg deliver the tightest possible 90-degree turn in this diameter, making it a go-to choice for chassis routing, turbocharger outlet plumbing, and compact exhaust sections on smaller displacement builds.
Features and Benefits
- 16-gauge (0.065in wall) 304 stainless steel resists exhaust heat and corrosion for long service life
- Mandrel-bent 1D tight radius at 1.75in CLR delivers the smallest footprint 90-degree bend possible in 1.75in tubing
- 2in leg provides usable trim material while minimizing the overall installed length
- Fully round bore prevents turbulence and maintains flow velocity through the bend
- Polished OD surface is TIG and MIG weld-ready after acetone cleaning
- Compact geometry suits tight turbo plumbing, inter-pipe routing, and downpipe fabrication on small-displacement engines
- Compatible with standard 1.75in exhaust clamps, slip-joints, and flanges
- Part of the Stainless Bros SS304 mandrel bend family for consistent fit and finish across a full build
Specifications
| Specification | Detail |
|---|---|
| Part Number | 601-04556-4100 |
| Brand | Stainless Bros |
| Material | 304 Stainless Steel |
| Wall Thickness | 16 gauge / 0.065in |
| Tube OD | 1.75in |
| Bend Radius | 1D / 1.75in CLR |
| Bend Angle | 90 Degree |
| Leg Length | 2in |
| Finish | Polished OD |
| Warranty | Stainless Bros limited warranty |
What's Included
- 1 x Stainless Bros 1.75in 90-degree 1D tight-radius mandrel bend (part 601-04556-4100)
- 2in straight leg
Frequently Asked Questions
What is the tube OD for the 601-04556-4100?
The outside diameter is 1.75 inches. Use 1.75in exhaust clamps, slip joints, or flanges when connecting this bend to adjacent pipe sections.
What is the CLR for this 1D mandrel bend at 1.75in?
The centerline radius (CLR) is 1.75 inches, equal to 1x the tube diameter. This is the tightest radius achievable by mandrel bending at this tube size, ideal for space-constrained routing.
Where is this bend typically used?
The 601-04556-4100 is commonly used in small-displacement turbo downpipes, exhaust mid-pipes, intercooler inlet and outlet plumbing, and tight-clearance header collector merge sections on four-cylinder and rotary engine builds.
How short is the leg on this bend?
The leg is 2 inches. For very tight installations, 2 inches provides just enough material to trim and weld. If you need more straight material, plan to add an extension tube section before or after the bend.
What weld filler rod is recommended for the 601-04556-4100?
ER308L for stainless-to-stainless joints and ER309L for stainless-to-mild-steel joints. TIG welding with argon back-purge is the preferred method for a clean, full-penetration weld.
Is the 1D tight radius going to cause excessive backpressure on a 1.75in exhaust?
In 1.75in diameter piping, a 1D bend typically causes a modest increase in restriction compared to a 1.5D bend. For most applications at this diameter, the difference is acceptable, especially when the alternative is a crush-bent pipe or a larger footprint that cannot fit the available space.
Can I use this bend in a 1.75in OD mild steel exhaust system?
Yes. Weld it in using ER309L filler rod for the dissimilar metal joint. The stainless section will outlast mild steel sections and is a practical upgrade for frequently replaced bend sections.
What are the overall dimensions of this bend including the arc and leg?
The 2-inch leg plus the 1.75in CLR arc results in a compact total footprint. For precise routing mockups, use the CLR and leg length to calculate the space needed before purchase.
Installation Instructions
- Confirm the available space in the routing path using a cardboard or wire mockup of the bend geometry before cutting existing tubing.
- Dry-fit the 601-04556-4100 to verify leg length is sufficient. Add extension straight sections if needed before welding.
- Mark and trim leg to required length with a tubing cutter or cutoff wheel.
- Deburr the cut end thoroughly to remove sharp edges.
- Clean weld areas with acetone before TIG or MIG welding.
- Tack in position, verify alignment, then complete circumferential welds.
- Inspect welds for full penetration and absence of leaks before final installation.
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