Brass Threepences were first minted in 1937, they ran alongside the Silver Threepences for the first few years, but from 1945-1967 they were the only Threepence struck.

Brass Threepences were the UK's first 12 sided coin, strictly speaking these coins were made from Nickel-Brass (79% Copper, 20% Zinc and 1% Nickel). The Brass Threepence weighed 6.6 grams and the diameter was 21 mm across the sides and 22 mm across the corners. 
Please see our Threepences in Brass Coins for sale below:

Threepences (Brass)

Item	Date	Description	Grade	Additional Desc	Price
Threepence (Brass)	1937		BU		£5.00	Buy
Threepence (Brass)	1937	Ed.VIII (5.49g)	UNC		£95.00	Buy
Threepence (Brass)	1937	Geo.VI Undated	EF	coin mostly removed leaving only the portrait in the flan	£85.00	Buy
Threepence (Brass)	1937	Proof	FDC		£22.50	Buy
Threepence (Brass)	1938		UNC		£25.00	Buy
Threepence (Brass)	1938		AUNC		£19.50	Buy
Threepence (Brass)	1939		AUNC		£35.00	Buy
Threepence (Brass)	1940		AUNC		£22.50	Buy
Threepence (Brass)	1941		AUNC		£7.50	Buy
Threepence (Brass)	1942		AUNC		£7.50	Buy
Threepence (Brass)	1943		AUNC		£7.50	Buy
Threepence (Brass)	1944		AUNC		£9.50	Buy
Threepence (Brass)	1945		AUNC		£15.00	Buy
Threepence (Brass)	1946		GVF+		£49.50	Buy
Threepence (Brass)	1946		GF+		£9.50	Buy
Threepence (Brass)	1946		F		£5.00	Buy
Threepence (Brass)	1946	Slabbed by ICG	MS-63		£595.00	Buy
Threepence (Brass)	1946	Slabbed by NGC	AU-55		£325.00	Buy
Threepence (Brass)	1948		AUNC		£49.50	Buy
Threepence (Brass)	1949		GEF		£295.00	Buy
Threepence (Brass)	1949		NEF		£95.00	Buy
Threepence (Brass)	1949		GVF		£35.00	Buy
Threepence (Brass)	1949		VF		£22.50	Buy
Threepence (Brass)	1949		GF		£9.50	Buy
Threepence (Brass)	1950		AUNC		£75.00	Buy
Threepence (Brass)	1950		EF		£25.00	Buy
Threepence (Brass)	1950		VF		£12.50	Buy
Threepence (Brass)	1950		GF		£6.00	Buy
Threepence (Brass)	1950	Proof	FDC		£44.00	Buy
Threepence (Brass)	1951		NEF		£29.50	Buy