Record summary

The Mustad Quality 3670 represents a classic European wet fly hook from the golden age of traditional fly fishing P. This size 8 specimen features the distinctive Limerick bend geometry with its characteristic angular bottom section, paired with a turned-up loop eye construction that was the hallmark of premium wet fly hooks P.

The black japanned finish provided excellent corrosion resistance while maintaining the traditional aesthetic preferred by classic fly tyers P. Dating from approximately 1950-1975 based on the Oslo-Norway geographic designation and cream box packaging style, this hook represents Mustad’s mid-century dominance in the European fly fishing market I.

The hollow point geometry visible on the specimen provides rapid penetration with minimal force, making it ideal for soft-mouthed trout and similar species P. This combination of Limerick bend, turned-up loop eye, and hollow point made the 3670 a favorite among traditional wet fly anglers and collectors of vintage tackle I.

Technical profile

Eye

Looped Eye, Turned Up The turned-up loop eye shows the characteristic oval shape with return wire running parallel to the shank P. This construction was specifically designed for snelling to gut leaders and represents premium manufacturing quality I.

Wire

Heavy (1X Heavy), Round

Shank

Standard — Plain

Bend

Limerick, Standard gap Classic Limerick geometry with distinct angular bottom section clearly visible P. The sharp angle at the bottom of the bend was designed to lock into the fish's jaw for secure hook sets I.

Point

Hollow Point (concave inner face) Standard-sized barb positioned close to the point with moderate angle P. Barb size is proportionate to hook size and designed for secure holding without excessive tissue damage E.

Finish

Black Japanned — Confirmed (stated on packaging) Deep black japanned finish with characteristic high-gloss appearance P. This traditional lacquer coating provided excellent rust resistance and was the preferred finish for classic wet fly hooks I.
Hooks show excellent condition with intact japanned finish and no corrosion P. Original cream-colored box displays light age toning but remains structurally sound with clear labeling P.

Historical context

mustad

O. Mustad & Søn transformed from a small Norwegian nail factory into the world’s largest hook manufacturer following Mathias Topp’s invention of the automated hook-making machine in 1877 V. Operating from their Gjøvik factory, Mustad achieved global dominance through industrial efficiency and aggressive reverse-engineering of regional hook patterns V. By the 1950s, Mustad controlled approximately 50% of the global hook production market, making their name virtually synonymous with fishing hooks worldwide V.

Series History

The 3670 was part of Mustad’s comprehensive wet fly hook lineup, designed to compete directly with traditional British manufacturers like Allcock and Sealey I. The model combined the popular Limerick bend geometry with premium construction features like the turned-up loop eye, positioning it as a high-quality alternative to Redditch-made hooks I. Production likely continued through the 1970s before being discontinued during Mustad’s product line rationalization S.

Era and Packaging Dating

Oslo-Norway geographic designation indicates post-1925 production when Christiania was renamed. Cream-colored box with gold foil lettering and Key Brand logo is characteristic of mid-century Mustad packaging. No barcode indicates pre-1974 production.

Design lineage and influence

The 3670 represents Mustad’s interpretation of classical British wet fly hook design, combining the traditional Limerick bend with Norwegian manufacturing efficiency I. This model competed directly with established British makers like Allcock’s traditional wet fly patterns and Sealey’s premium offerings I. The design influenced later Mustad wet fly hooks while maintaining the traditional construction methods that defined mid-century European fly fishing S.

Best matchRelated by Attribute

Computed automatically from catalog data — updated as new hooks are added.

Silhouette	Hook Model	Match	Analysis	Compare
	90240 No. 8 — Mustad 90240 Low Water Salmon Hook	79%	Matches: Bend, Shank, Gap, Eye, Eye Orient. +5 moreDiffers: Wire: Heavy (1X Heavy) vs Fine (1X Fine); Application: Wet Fly, Streamer vs Salmon, Sea Trout	Compare
	1921 R No. 9 — Limerick Hooks	78%	Matches: Bend, Shank, Wire, Gap, Point +3 moreDiffers: Eye: Looped Eye vs Tapered Eye; Eye Orient.: Turned Up vs Turned Down; Finish: Black Japanned vs Bronzed +1 more	Compare
	9009 No. 8 — Mustad 9009	78%	Matches: Bend, Gap, Eye, Point, Forging +2 moreDiffers: Shank: Standard vs 1X Long; Wire: Heavy (1X Heavy) vs Extra-Heavy (2X+); Eye Orient.: Turned Up vs Turned Down +2 more	Compare
	7111 B No. 2/0, 6/0 — Mustad 7111B Limerick	77%	Matches: Bend, Shank, Wire, Gap, Finish +3 moreDiffers: Eye: Looped Eye vs Ball Eye; Eye Orient.: Turned Up vs Turned Down; Point: Hollow Point vs Superior +1 more	Compare
	36814 No. 6 — Mustad 36814 Limerick	76%	Matches: Bend, Shank, Gap, Eye, Eye Orient. +4 moreDiffers: Wire: Heavy (1X Heavy) vs Standard; Forging: Round vs Forged; Application: Wet Fly, Streamer vs Salmon, Sea Trout	Compare

ExploratoryRelated by Shape (SVG)

Ranked purely by silhouette geometry — attribute labels are ignored.

Silhouette	Hook Model	Match	Compare
	K14ST No. 16 — K14ST Nymph/Emerger	100%	Compare
	3718 No. 4 — Herter's No. 3718 Salmon Fly Hook	99%	Compare
	5795 No. 12 — Mustad 5795	98%	Compare
	9166 No. 12 — Mustad 9166 Crystal Hook	98%	Compare
	80 No. 2 — Eagle Claw	98%	Compare

Cross-reference & comparisons

Primary Application

Classic wet fly hook designed for traditional winged wet flies and small streamers P. The turned-up loop eye was specifically engineered for snelling to gut leaders, making this a premium choice for European-style wet fly fishing I. The Limerick bend geometry provides secure hook sets and excellent fish-holding power for trout and similar species P.

Secondary Applications

Small bait fishing applications, traditional salmon fly tying

Classic Fly Patterns

Traditional winged wet flies, Bergman series patterns, classic loch flies, small bucktail streamers

Modern Equivalents

Collector notes

Strong collector interest due to classic wet fly design and traditional construction features, with moderate rarity in good condition.

This hook appeals strongly to collectors of vintage wet fly tackle and traditional Norwegian fishing equipment I. The combination of Limerick bend and turned-up loop eye represents classic European fly fishing heritage that resonates with traditional fly fishing enthusiasts I. The japanned finish and cream box packaging add aesthetic appeal for display purposes P.

Availability is somewhat limited as most surviving examples show wear or corrosion, making pristine specimens like this more desirable E. However, the 3670 was not a rare or limited production model, which moderates collector demand compared to more scarce vintage hooks I.

Packaging

Cream-colored cardboard box with gold foil lettering and decorative border. Features Key Brand logo with skeleton key graphic. Eight-line Mustad label format clearly visible on top panel. Size marking '12' handwritten in purple on end panel.

Market Value Notes

Prices vary significantly based on packaging condition and completeness. Loose hooks bring $1-3 each, while complete boxes in excellent condition command premium pricing.

Where to Find

eBay vintage tackle listings, European fishing tackle fairs, specialized vintage fly fishing dealers, estate sales in traditional fishing regions