problem converting float into nvarchar

I have a problem converting a float filed into nvarchar.
select cast(sold as varchar(50))
where sold=431597.15 results in 431597 and is ignoring always my decimals.
Do you have any idea how to fix this?
tyHi

The below works for me:
DECLARE @.Sold AS Float
SELECT @.Sold = 431597.15
SELECT CAST(@.Sold AS VarChar(50)) --Wrong
SELECT CAST(CAST(@.Sold AS Decimal(8, 2)) AS VarChar(50))--Correct

HTH