Arnold & Son · Royal Collection

Strap for TB88

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter46 mm
Reference1TBAS.B01A.C113S
FamilyRoyal Collection
MovementArnold & Son caliber A&S5003 NAC hours, jumping seconds, minutes, small seconds
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the Royal Collection 1TBAS.B01A.C113S

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Royal Collection 1TBAS.B01A.C113S, seen from the bench

The Arnold & Son Royal Collection 1TBAS.B01A.C113S is a 46mm stainless steel chronograph featuring the Arnold & Son calibre A&S5003 NAC movement with jumping hours, continuous minutes, small seconds, and precisely arranged counters. The 20mm lug width follows the standard of reference British chronographs, proportioned to balance the substantial case diameter with the strap. This independent British watchmaking piece integrates the case and strap as equal architectural elements, rejecting generic design in favor of studied proportions and visible mechanics.

Frequently asked questions

What is the lug width of the Arnold & Son Royal Collection 1TBAS.B01A.C113S?

The lug width of this model is 20 millimetres. This is a standard width for chronographs of this case diameter, maintaining correct visual proportions between the 46mm case and the strap. The 20mm measurement represents the design equilibrium between case mass and strap lightness—a deliberate choice by Arnold & Son's manufacture to ensure aesthetic harmony.

Which strap is recommended for the Royal Collection 1TBAS.B01A.C113S?

For a chronograph of this calibre, we recommend straps in alligator with vegetable tanning (cognac, deep mahogany or black), or box calf in burgundy or black for those preferring natural patina development over time. For sport configurations, a NATO in natural weave or a natural rubber strap in black offer durability and versatility. The steel deployante buckle enables micrometric adjustment ideal for 20mm lugs.

How do I change the strap on my Arnold & Son Royal Collection?

Strap replacement requires a specific tool called a spring bar remover, allowing lateral movement of the lug to disengage the strap from the case's metal lug socket. Since the lug is integrated to the Royal Collection, it remains fixed: the strap slides between two anchorage points. We recommend operating with care and a stable work surface, or entrust the operation to a specialised watchmaker. Atelier Casati Milano offers strap change services by appointment for those seeking professional execution.

Is an aftermarket 20mm strap compatible with the Arnold & Son 1TBAS.B01A.C113S?

Yes, any strap with a 20mm lug width is compatible with this model, regardless of brand or material. What matters is appropriate strap thickness (typically 2.5–3.5mm) and perfect alignment of anchorage points. Milano Straps maintains a comprehensive catalogue of artisanal 20mm straps verified for dimension and construction quality.

How long does a leather strap last on an Arnold & Son Royal Collection?

A high-quality alligator strap with vegetable tanning, worn with seasonal rotation (not daily), maintains structural integrity for 8–12 years. Durability depends on use, climate and maintenance. A box calf strap subjected to daily wear typically lasts 4–6 years before restoration. Natural rubber lasts 5–7 years. With vegetable tanning, the material develops intentional patina and creasing that amplifies ageing aesthetics. We recommend alternating straps and storing unused straps in a dry environment.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

Request an appointment →

Casati Milano · Via XX Settembre 15, Milan · by appointment only