Purdue University	Mimeo AE 47 ,
Cooperative Extension Service	
Lafayette, Indiana
LIST OF APPROVED DRAIN TILE MANUFACTURERS
By Donald R. Sisson, Extension Agricultural Engineer
High quality drain tile are required for a durable, long-lasting tile drainage system. The American Society for Testing Materials (ASTM) has set up specifications for drain tile. Every tile user is urged to purchase only tile meeting these ASTM standards. Three classes or grades are recognized for both clay and concrete tile. Physical test requirements are shown in the table below. Landowners must use at least "standard" quality tile to qualify for government incentive payments on tile drainage through the soil conservation program.
Other requirements are that the tile be sound and give a clear ring when tapped with a light hammer, that they be about straight in length and circular in cross-section, reasonably smooth on the inside and free from blisters, checks and cracks that would decrease strength.
In Indiana, through a cooperative program, a list of approved tile manufac-
turers is published each May lb and October 15. Tile manufacturers, the Soil Conservation Service and Purdue University make this list possible. Each tile manufacturer who cares to participate has a strength and absorption test performed on e sample of drain tile during the 90 days preceding the date the list is issued. Technicians of the Soil Conservation Service select the samples at the manufacturer's yard. The producer transports the tile to the independent laboratory of his choice and pays for the tests. Only manufacturers whose tile meet or surpass the "standard" quality requirements are included on the list. The approved list of manufacturers distributing tile in Indiana as of October 15, 1962 follows. This list is effective until a new list is published about May 15, 1963.
Drain tile manufactured in Indiana or other states that are tested under an equivalent or better procedure are also eligible for use in Indiana.
ASTM physical test requirements for drain tile, sizes 4 to 12 inch diameter, inclusive specification C412-60 for concrete and C4-59T for clay.
Class of tile	Minimum average crushing strength by 3-edge bearing method		Maximum average absorption by 5-hour boiling	
	Clay	Concrete	Clay	Concrete
	lb per :	lineal foot	percent	
Standard	800	800	13	10
Extra-quality	1,100	1,100	11	9
Heavy-duty	1.400 to 1,700 			11	—
Spec ial-quality		1,100		8
fa + ^ra^n "tile manufacturers passing the Indiana test requirements and Indiana manu-c urers meeting equivalent or better test requirements in other states follow: