466 REPORT ON COOPERATION IN AMERICAN EXPORT TRADE.
quest of the customer. In such cases the convention bureau, however, has to
exercise the controlling function. (General meeting 20.2.14.)

ABNORMAL BEARINGS OUTSIDE OF THE STANDARD SERIES AND EXTENDED BEARINGS.
Extended series are accepted in.accordance with the proposition of D. W. F.
(General meeting 20.1.14.)
Intermediate sizes of the extended series are computed in accordance with
the D. W. F. formula. (General meeting 20.1.14.)
Quotations on abnormal bearings which can be proven to be in effect remain
In effect without any regard to possible changes in the provisions of the convention
 for computing such bearings for a term of three months after making
the quotation. The binding term may be extended to a full year on motion of
the customer. - In such cases the convention bureau must exercise the function
of control. (General meeting 20.2.14.)
The ball mean circle must never be smaller than the mean between bore hole
and outside diameter (race mean circle), but it may be greater.
As the guiding prices for series 700, 200, 300, 400, 1000, and 1100, the quotations
 made by the D. W. F., which every firm has received. will be considered.

Further guiding price tables covering missing series PJL, 1200, 1300, likewise
 two theoretical end series each for race systems and thrust-ball bearings,
and intermediate series for thrust-ball bearings, will be furnished shortly by the
firm named. ,
These guiding prices also apply to tension socket bearings of the extended
series by adding the prices for the tension sockets which, it is true, still have
to be regulated.
Double-row bearings which are equal to the bearings of the extended series
In the matter of outside diameter and bore, must also be figured by using the
guiding prices of the extended series and an addition of 70 per cent must be
made to the basic prices of the one-row bearings.
Abnormal bearings within the extended series must be calculated according
to the formula mentioned helow. The governing prices to be used in the calculation
 are composed of the basic price of the standard comparison bearing and
the additional percentages or allowances, mentioned in the guiding tables, to be
computed in connection with the quantities deviating from the normal manufacturing
 quantities.
The D. W. F. formula reads:

pg 2P'+P:. Dm. id}
(Dm!+¥Dm?), (1d3-+idP)
In this formula the abbreviations mean:
P'—Guiding price of the smaller comparison bearing.
P’—Price of the bearing wanted.
P*—Governing price of the larger comparison bearing.
Dm*—Ball mean circle of the smaller comparison bearing.
Dm?—Ball mean circle of the bearing wanted.

Dm*—Ball mean price of the larger comparison bearing.
The value id® is the product from the full number of balls and the square of
the ball size (ball size in 1/8’).

Bzrample.

Let a bearing have as a full complement 20 balls of 1}’’ diameter, then the
id? is )
20 X 12° (as 13’ = 12/8).
The id* therefore amounts to 2880.
In the formula:
1d® is the value of the smaller comparison bearing.
id 3 the valug of the bearing wanted.
id the value of the larger comparison bearing.
Wa in this connection examples of the D. W. F. in their circular of