Transact SQL :: Convert Comma Separated String Values Into Integer Values

I have a string variable

string str1="1,2,3,4,5";

I have to use the above comma separated values into a SQL Search query whose datatype is integer. How would i do this Search query in the IN Operator of SQL Server. My query is :

declare @id varchar(50)
set @id= '3,4,6,7'
set @id=(select replace(@id,'''',''))-- in below select query Id is of Integer datatype
select *from ehsservice where id in(@id)

But this query throws following error message:

Conversion failed when converting the varchar value '3,4,6,7' to data type int.