22 
BULLETIN 555, U. S. DEPARTMENT OF AGRICULTURE. 
Methods of 
samp Ii n g a u d 
grading. 
The mineral filler shall be sampled for quality and grading in 
accordance with the method described on page , para- 
graph , of these specifications; and the grading shall 
be determined in accordance with the method described or re- 
ferred to on page of these specifications, test Xo. 
SPECIFICATION FOR ROAD OILS FOR COLD APPLICATION. 
General. 
Fhjsical and 
chemical proper- 
ties. 
Methods of 
testing. 
The road oil shall be homogeneous and free from water. 
It shall meet the following requirements : 
1. 
Specific gravity 25°/25° C. (77°/77° F.). to 
2 # 
Flash point, not less than ° C. ( F.). 
[or ° C, ( ° F.) to ° C. ( ° F.)*] 
3. 
Specific viscosity at ° C.t ( ° F.), to 
4. 
Loss at 163° C. (325° F.), 5 hours, not more than %. 
(o?~ to per cent.*) 
1(c) Float test of residue at 50° C. (122° F.), 
to sec. 
5. Total bitumen (soluble in carbon disulphide) not less than 
per cent. 
6. Per cent of total bitumen insoluble in 86° B. naphtha. 
to 
Tests of the physical and chemical properties of the road oil 
shall be made in accordance with the methods described or re- 
ferred to on page of these specifications, tests Nos. 
Notes. — (1) In some instances it may be considered desirable 
to include a requirement for loss at 105° C. (221° F.), in which 
case the wording should be: Loss at 105° C. (221° F.), 5 hours, 
not less than per cent. 
(2) In some instances it may be considered desirable to in- 
clude a requirement for the percentage of residue of pene- 
tration, in which case the wording should be: Percentage of 
residue of penetration, to 
(3) In certain cases the inclusion of all the tests listed or noted 
may not be desirable, but it is necessary to use certain combina- 
tions of the tests in order to secure a material suitable for a 
specified purpose. 
General. 
Physical and 
chemical proper- 
ties. 
SPECIFICATION FOR ROAD OILS FOR HOT APPLICATION. 
The road oil shall be homogeneous, free from water, and shall 
not foam when heated to ° C. ( ° F.). 
It shall meet the following requirements : 
1. Specific gravity 25°/25° C. (77°/77° F.), to 
* In cases where the presence of a volatile or light flux is desired the 
second form of the flash-point iequirement and of the loss at 163° C. 
requirement should be used ; in all other cases the first form of require- 
ment is applicable. 
f It is recommended that the viscosity determination be made at 
25° C. (77° F.) or 40° C. (104° F.), according to the nature of the 
product desired. 
t In case the oil is to be used as a dust layer only, this requirement 
Is to be omitted. 
