Name: IWC Portofino Automatic 40mm IW356501
Brand: IWC
SKU: IW356501

The Portofino Automatic 40mm is IWC's cleanest dress watch at the most accessible entry point in the lineup. Its slim case, restrained silver sunburst dial, and central seconds with a discreet date at 3 make it a legitimate alternative to Longines or Frederique Constant at a fraction of the Portugieser's price. Collectors who want IWC provenance on the wrist without the bulk of a pilot watch or the expense of the Portugieser start here.

What it is

IWC has offered Portofino dress automatics since the 1980s, but the current 40mm generation with the IW356501 reference settled into its mature form around 2019. The caliber 35111 is a modified Sellita SW300-1, which traces its own lineage to the ETA 2892. IWC rates it at 50 hours of power reserve with a frequency of 28,800 vph.

Dial variants across the line include silver, blue, and black, with the silver sunburst being the most requested. No significant references have been discontinued in this generation, though earlier Portofino rounds in 37mm and 39mm represent an older design language that some collectors prefer for its thinner bezel.

Buying notes

The Sellita SW300-1 base is not a secret, and some buyers feel the retail price is hard to justify for what is, mechanically, a mid-tier Swiss lever movement. Inspect the dial carefully: the Portofino's sunburst finish shows fingerprints and fine scratches from careless handling, and a marred dial is the most common discount reason on the grey market. Check the case for polishing.

The lugs on the 40mm are narrow enough that an overzealous polish rounds them quickly and flattens the brushed flanks. Bracelet wear is not an issue since the IW356501 ships on a leather strap, but examine the lug holes for wear if a prior owner used an aftermarket metal bracelet adapter.

Market read

New retail runs roughly $4,500 to $5,000 USD depending on dial color and strap. The grey market sits 15 to 25 percent below retail, making the IW356501 one of the easier IWC references to find under $4,000 in near-new condition. Blue dials carry a modest premium over silver, consistent with broader market preference.

The Portofino does not appreciate; it is a use-and-enjoy piece, not a store of value.

Service expectations

The caliber 35111 (Sellita SW300-1 base) is straightforward to service, and IWC recommends a service interval of around 5 years. Expect $400 to $700 USD at an independent watchmaker and $800 to $1,200 at an IWC service center, depending on whether seals and worn parts need replacement. The movement's common lineage means parts availability is better than for many in-house calibers.

Editorial copy is AI-drafted from primary sources and reviewed by Grail Atlas before publication. Where the text is uncertain about a fact, it says so. Email corrections@grailatlas.com if something reads wrong. Signals on this page (community, OSINT) are clearly separated from the editorial sections.

Mass-produced#1 in family

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In-house manufacture caliber · caliber IWC Caliber 35111 (automatic, date, 50-hour power reserve) · 50h power reserve (2.1 days)

Medium-large: suits wrists 6.5 in+ (16.5 cm+)

40 mm case. Wears confidently on average to larger wrists. May overhang on slender builds.

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Authentication

The Portofino dial is thin and delicate; crack repairs on the silver or white dial are the highest-stakes cosmetic issue on used examples.

Known issues in the market

Silver and white lacquer dials are prone to cracking; crack repairs are sometimes attempted and must be inspected under magnification.
The 35111 uses an ETA base movement, which is appropriate for this category but should be priced accordingly.

Area	What to check	What is correct	Red flag
dial	Dial surface condition	Dial surface smooth and crack-free under magnification; no repaired or filled cracks; consistent lacquer finish	Hairline cracks visible under loupe; filled or repaired cracks; inconsistent lacquer surface indicating repair
caseback	Cal. 35111 ETA base movement	ETA base movement visible; IWC decoration applied; architecture consistent with Cal. 35111	Non-ETA architecture; missing IWC decoration indicating service that removed finishing
case	Case condition and finishing	Polished round case in clean condition; correct lug proportions for 40mm Portofino	Case polished to remove scratches in a way that rounds the lugs; incorrect lug proportions from a different Portofino generation

Common legitimate replacements

Leather straps are the only configuration; IWC-logo buckle is preferred.
Dials are the most consequential replacement; any dial replacement must be disclosed and significantly affects value.

Expert resources: IWC serial number verification. Inspect the dial under 10x loupe in raking light to reveal hairline cracks. WatchUSeek IWC forum for Portofino dial condition documentation.

Authentication guide

Last reviewed September 2026

The IW356501 is the steel 40mm Portofino Automatic with central hacking seconds and a date at 3 o'clock, powered by Cal. 35111 (a modified Sellita SW300-1, whose lineage traces back to the ETA 2892). The Portofino is IWC's most accessible dress watch line; the thin case, the silver sunburst dial with applied Roman numerals only at XII and VI over baton indexes, and the printed railway minute track are the signatures. The caseback is solid steel, not a display back.

Known reproduction risks

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MEDIUM

Replica Portofinos with incorrect dial detailing or a wrong caseback

The Roman numerals appear only at XII and VI and should be applied polished metal with crisp edges; replicas often print all markers or apply a full Roman chapter ring the genuine dial does not have
The printed railway minute track (with the red 60 at 12) is finely and evenly spaced on genuine dials; replicas show uneven spacing or a wrong shade of red
Dial finishing on replicas is often too matte or too glossy relative to the genuine silver sunburst character
The genuine caseback is solid steel with an engraved PORTOFINO ring; any example showing an exhibition/display back is not a genuine IW356501

The Portofino is targeted less aggressively than the Portugieser due to its lower secondary market value.

Dial variants by era

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Era	Description	Identifiers
2019 to present	Silver sunburst dial with applied Roman numerals only at XII and VI and applied baton (stick) indexes at every other hour. A printed railway-style minute/seconds track with Arabic five-minute markers (and a red 60 at 12) runs around the dial perimeter. Date window at 3 o'clock, dauphine-style polished hands, and a central hacking seconds hand. Steel-dial line also offered with blue and black dials.	Applied Roman numerals only at XII and VI; polished baton indexes at all other hours (not a full Roman chapter ring) Printed railway minute/seconds track around the perimeter with a red 60 at 12 o'clock Date window at 3 o'clock; central hacking seconds (no sub-seconds) "IWC / SCHAFFHAUSEN" printed below 12 and "AUTOMATIC" above 6 o'clock Thin case profile appropriate for a dress watch; black alligator leather strap as standard

Service part flags

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Movement

Original: Cal. 35111, a modified Sellita SW300-1 with IWC finishing and an IWC-signed rotor; the SW300-1 lineage traces back to the ETA 2892. It runs at 28,800 vph (4 Hz) with 25 jewels, and iwc.com currently publishes a 50-hour power reserve. The caliber is not in-house but is regulated to IWC's standard.

Replacement tells

A bare Sellita SW300-1 (or ETA 2892) without IWC finishing or an IWC-branded rotor
Service documentation that does not reference Cal. 35111 specifically (older paperwork may still cite the superseded Cal. 35100 / ETA 2892)

Case back markings

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2019 to present

Solid (closed) stainless steel caseback with a brushed sunburst center; the Portofino Automatic 40 does not have a display/exhibition back, so the movement is not visible in normal wear
Engraved caseback ring reads PORTOFINO and INTERNATIONAL WATCH CO. SCHAFFHAUSEN
Reference IW356501 and the individual serial number engraved with the caseback
No soft iron cage (the Portofino is not an anti-magnetic reference)

Movement tells

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Cal. 35111 runs at 28,800 vph (4 Hz) with 25 jewels and, per iwc.com, a 50-hour power reserve. Because the caseback is solid, the movement cannot be inspected without opening the watch; at service, an IWC-signed rotor and IWC finishing should be present, while a bare Sellita SW300-1 or ETA rotor indicates a non-original or swapped movement.

Sources: IWC Portofino Automatic IW356501 product page; WatchUSeek -- Portofino IW356501 thread.